US20100190639A1 - High surface area, electrically conductive nanocarbon-supported metal oxide - Google Patents
High surface area, electrically conductive nanocarbon-supported metal oxide Download PDFInfo
- Publication number
- US20100190639A1 US20100190639A1 US12/694,425 US69442510A US2010190639A1 US 20100190639 A1 US20100190639 A1 US 20100190639A1 US 69442510 A US69442510 A US 69442510A US 2010190639 A1 US2010190639 A1 US 2010190639A1
- Authority
- US
- United States
- Prior art keywords
- carbon
- metal oxide
- aerogel
- composite
- tio
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 229910044991 metal oxide Inorganic materials 0.000 title claims abstract description 51
- 150000004706 metal oxides Chemical class 0.000 title claims abstract description 51
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 171
- 239000002131 composite material Substances 0.000 claims abstract description 133
- 239000002041 carbon nanotube Substances 0.000 claims abstract description 111
- 229910021393 carbon nanotube Inorganic materials 0.000 claims abstract description 110
- 239000004966 Carbon aerogel Substances 0.000 claims abstract description 85
- 239000004964 aerogel Substances 0.000 claims abstract description 71
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 63
- 229910052751 metal Inorganic materials 0.000 claims abstract description 53
- 239000002184 metal Substances 0.000 claims abstract description 53
- 238000001035 drying Methods 0.000 claims abstract description 13
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 411
- 239000000499 gel Substances 0.000 claims description 39
- 239000003054 catalyst Substances 0.000 claims description 17
- 238000004519 manufacturing process Methods 0.000 claims description 17
- 239000004408 titanium dioxide Substances 0.000 claims description 16
- 239000011240 wet gel Substances 0.000 claims description 16
- 239000011248 coating agent Substances 0.000 claims description 14
- 238000000576 coating method Methods 0.000 claims description 14
- 239000011541 reaction mixture Substances 0.000 claims description 13
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 9
- 239000010949 copper Substances 0.000 claims description 8
- 239000000725 suspension Substances 0.000 claims description 8
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 6
- 229910052802 copper Inorganic materials 0.000 claims description 6
- 229910052742 iron Inorganic materials 0.000 claims description 6
- 229910052759 nickel Inorganic materials 0.000 claims description 6
- 229910052725 zinc Inorganic materials 0.000 claims description 6
- 239000011701 zinc Substances 0.000 claims description 6
- 229910052726 zirconium Inorganic materials 0.000 claims description 6
- 229910052748 manganese Inorganic materials 0.000 claims description 5
- 239000011572 manganese Substances 0.000 claims description 5
- 229910052718 tin Inorganic materials 0.000 claims description 5
- 239000012736 aqueous medium Substances 0.000 claims description 4
- 239000000376 reactant Substances 0.000 claims description 4
- 229910052710 silicon Inorganic materials 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical compound CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 claims description 3
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims description 3
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 3
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- 229910017052 cobalt Inorganic materials 0.000 claims description 3
- 239000010941 cobalt Substances 0.000 claims description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 3
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 2
- 150000004703 alkoxides Chemical class 0.000 claims description 2
- 239000002243 precursor Substances 0.000 claims description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims 1
- 229910052804 chromium Inorganic materials 0.000 claims 1
- 239000011651 chromium Substances 0.000 claims 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims 1
- 150000003839 salts Chemical class 0.000 claims 1
- 239000010703 silicon Substances 0.000 claims 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 100
- 239000000377 silicon dioxide Substances 0.000 description 49
- 239000011148 porous material Substances 0.000 description 46
- 229910052681 coesite Inorganic materials 0.000 description 43
- 229910052906 cristobalite Inorganic materials 0.000 description 43
- 239000000463 material Substances 0.000 description 43
- 229910052682 stishovite Inorganic materials 0.000 description 43
- 229910052905 tridymite Inorganic materials 0.000 description 43
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 32
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 30
- 229910010271 silicon carbide Inorganic materials 0.000 description 27
- 229910003465 moissanite Inorganic materials 0.000 description 26
- 230000015572 biosynthetic process Effects 0.000 description 25
- 239000006260 foam Substances 0.000 description 25
- 238000000034 method Methods 0.000 description 24
- 239000002245 particle Substances 0.000 description 22
- 230000009467 reduction Effects 0.000 description 22
- 238000003786 synthesis reaction Methods 0.000 description 21
- 239000010410 layer Substances 0.000 description 18
- 229910052757 nitrogen Inorganic materials 0.000 description 18
- GHMLBKRAJCXXBS-UHFFFAOYSA-N resorcinol Chemical compound OC1=CC=CC(O)=C1 GHMLBKRAJCXXBS-UHFFFAOYSA-N 0.000 description 18
- 238000002441 X-ray diffraction Methods 0.000 description 17
- 238000004458 analytical method Methods 0.000 description 17
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 16
- 238000012512 characterization method Methods 0.000 description 15
- 239000000243 solution Substances 0.000 description 15
- XOJVVFBFDXDTEG-UHFFFAOYSA-N Norphytane Natural products CC(C)CCCC(C)CCCC(C)CCCC(C)C XOJVVFBFDXDTEG-UHFFFAOYSA-N 0.000 description 14
- 238000004626 scanning electron microscopy Methods 0.000 description 14
- 238000002411 thermogravimetry Methods 0.000 description 14
- 238000006243 chemical reaction Methods 0.000 description 13
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 13
- 239000002109 single walled nanotube Substances 0.000 description 13
- 239000010936 titanium Substances 0.000 description 13
- 238000004627 transmission electron microscopy Methods 0.000 description 13
- 238000010438 heat treatment Methods 0.000 description 12
- 239000000523 sample Substances 0.000 description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 12
- 239000012071 phase Substances 0.000 description 11
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 10
- 229910052719 titanium Inorganic materials 0.000 description 10
- 150000004767 nitrides Chemical class 0.000 description 9
- 238000002485 combustion reaction Methods 0.000 description 8
- 238000012986 modification Methods 0.000 description 8
- 230000004048 modification Effects 0.000 description 8
- 239000002159 nanocrystal Substances 0.000 description 8
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 7
- 238000003917 TEM image Methods 0.000 description 7
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 7
- 230000007423 decrease Effects 0.000 description 7
- 238000009826 distribution Methods 0.000 description 7
- 238000001764 infiltration Methods 0.000 description 7
- 230000008595 infiltration Effects 0.000 description 7
- 150000001247 metal acetylides Chemical class 0.000 description 7
- 230000003647 oxidation Effects 0.000 description 7
- 238000007254 oxidation reaction Methods 0.000 description 7
- -1 transition metal nitrides Chemical class 0.000 description 7
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 6
- GVGUFUZHNYFZLC-UHFFFAOYSA-N dodecyl benzenesulfonate;sodium Chemical compound [Na].CCCCCCCCCCCCOS(=O)(=O)C1=CC=CC=C1 GVGUFUZHNYFZLC-UHFFFAOYSA-N 0.000 description 6
- 230000006872 improvement Effects 0.000 description 6
- 238000000634 powder X-ray diffraction Methods 0.000 description 6
- 238000001878 scanning electron micrograph Methods 0.000 description 6
- 229940080264 sodium dodecylbenzenesulfonate Drugs 0.000 description 6
- 230000000694 effects Effects 0.000 description 5
- 229960004279 formaldehyde Drugs 0.000 description 5
- 235000019256 formaldehyde Nutrition 0.000 description 5
- 239000011521 glass Substances 0.000 description 5
- 229910002804 graphite Inorganic materials 0.000 description 5
- 239000010439 graphite Substances 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 229910052760 oxygen Inorganic materials 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- JMXKSZRRTHPKDL-UHFFFAOYSA-N titanium ethoxide Chemical compound [Ti+4].CC[O-].CC[O-].CC[O-].CC[O-] JMXKSZRRTHPKDL-UHFFFAOYSA-N 0.000 description 5
- 229910052723 transition metal Inorganic materials 0.000 description 5
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- 238000013459 approach Methods 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 4
- 238000006555 catalytic reaction Methods 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 4
- 239000002079 double walled nanotube Substances 0.000 description 4
- 238000004146 energy storage Methods 0.000 description 4
- 210000003041 ligament Anatomy 0.000 description 4
- 239000002071 nanotube Substances 0.000 description 4
- 230000006911 nucleation Effects 0.000 description 4
- 238000010899 nucleation Methods 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical class [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 description 4
- 230000002829 reductive effect Effects 0.000 description 4
- 238000002336 sorption--desorption measurement Methods 0.000 description 4
- 239000011135 tin Substances 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 3
- 230000002902 bimodal effect Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000001879 gelation Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 239000012299 nitrogen atmosphere Substances 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- 238000000550 scanning electron microscopy energy dispersive X-ray spectroscopy Methods 0.000 description 3
- 229910000029 sodium carbonate Inorganic materials 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- YUYCVXFAYWRXLS-UHFFFAOYSA-N trimethoxysilane Chemical compound CO[SiH](OC)OC YUYCVXFAYWRXLS-UHFFFAOYSA-N 0.000 description 3
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 230000004913 activation Effects 0.000 description 2
- 238000000137 annealing Methods 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000008367 deionised water Substances 0.000 description 2
- 229910021641 deionized water Inorganic materials 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 239000006232 furnace black Substances 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 230000014759 maintenance of location Effects 0.000 description 2
- 238000013507 mapping Methods 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 229910021392 nanocarbon Inorganic materials 0.000 description 2
- 239000002086 nanomaterial Substances 0.000 description 2
- 239000002105 nanoparticle Substances 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 230000001699 photocatalysis Effects 0.000 description 2
- 239000011941 photocatalyst Substances 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000012703 sol-gel precursor Substances 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000003860 storage Methods 0.000 description 2
- 239000011232 storage material Substances 0.000 description 2
- 238000000194 supercritical-fluid extraction Methods 0.000 description 2
- 238000001757 thermogravimetry curve Methods 0.000 description 2
- 150000003623 transition metal compounds Chemical class 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- 229910002483 Cu Ka Inorganic materials 0.000 description 1
- 238000001069 Raman spectroscopy Methods 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229910020781 SixOy Inorganic materials 0.000 description 1
- 238000005411 Van der Waals force Methods 0.000 description 1
- 229960000583 acetic acid Drugs 0.000 description 1
- 238000005903 acid hydrolysis reaction Methods 0.000 description 1
- 230000003213 activating effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000013590 bulk material Substances 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 229920001940 conductive polymer Polymers 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 230000003292 diminished effect Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000012983 electrochemical energy storage Methods 0.000 description 1
- 238000001493 electron microscopy Methods 0.000 description 1
- 238000000921 elemental analysis Methods 0.000 description 1
- HHFAWKCIHAUFRX-UHFFFAOYSA-N ethoxide Chemical compound CC[O-] HHFAWKCIHAUFRX-UHFFFAOYSA-N 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000008098 formaldehyde solution Substances 0.000 description 1
- 239000012362 glacial acetic acid Substances 0.000 description 1
- 239000000017 hydrogel Substances 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 1
- 239000002114 nanocomposite Substances 0.000 description 1
- 238000002429 nitrogen sorption measurement Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
- 230000037361 pathway Effects 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000010298 pulverizing process Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 238000011946 reduction process Methods 0.000 description 1
- 230000002787 reinforcement Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 229960001755 resorcinol Drugs 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 229940001593 sodium carbonate Drugs 0.000 description 1
- 238000003980 solgel method Methods 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 238000010189 synthetic method Methods 0.000 description 1
- 230000004584 weight gain Effects 0.000 description 1
- 235000019786 weight gain Nutrition 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
- H01B1/08—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
- B01J21/063—Titanium; Oxides or hydroxides thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/18—Carbon
- B01J21/185—Carbon nanotubes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/30—Catalysts, in general, characterised by their form or physical properties characterised by their physical properties
- B01J35/39—Photocatalytic properties
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/08—Heat treatment
- B01J37/082—Decomposition and pyrolysis
- B01J37/084—Decomposition of carbon-containing compounds into carbon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B82—NANOTECHNOLOGY
- B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
- C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
- C04B35/528—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite obtained from carbonaceous particles with or without other non-organic components
- C04B35/532—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite obtained from carbonaceous particles with or without other non-organic components containing a carbonisable binder
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/624—Sol-gel processing
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
- C04B35/62605—Treating the starting powders individually or as mixtures
- C04B35/62645—Thermal treatment of powders or mixtures thereof other than sintering
- C04B35/62655—Drying, e.g. freeze-drying, spray-drying, microwave or supercritical drying
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
- C04B35/71—Ceramic products containing macroscopic reinforcing agents
- C04B35/78—Ceramic products containing macroscopic reinforcing agents containing non-metallic materials
- C04B35/80—Fibres, filaments, whiskers, platelets, or the like
- C04B35/83—Carbon fibres in a carbon matrix
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/22—Electrodes
- H01G11/30—Electrodes characterised by their material
- H01G11/32—Carbon-based
- H01G11/36—Nanostructures, e.g. nanofibres, nanotubes or fullerenes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/22—Electrodes
- H01G11/30—Electrodes characterised by their material
- H01G11/46—Metal oxides
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G11/00—Hybrid capacitors, i.e. capacitors having different positive and negative electrodes; Electric double-layer [EDL] capacitors; Processes for the manufacture thereof or of parts thereof
- H01G11/84—Processes for the manufacture of hybrid or EDL capacitors, or components thereof
- H01G11/86—Processes for the manufacture of hybrid or EDL capacitors, or components thereof specially adapted for electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/50—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of manganese
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/52—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of nickel, cobalt or iron
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/62—Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M4/624—Electric conductive fillers
- H01M4/625—Carbon or graphite
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3231—Refractory metal oxides, their mixed metal oxides, or oxide-forming salts thereof
- C04B2235/3232—Titanium oxides or titanates, e.g. rutile or anatase
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/34—Non-metal oxides, non-metal mixed oxides, or salts thereof that form the non-metal oxides upon heating, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
- C04B2235/3418—Silicon oxide, silicic acids or oxide forming salts thereof, e.g. silica sol, fused silica, silica fume, cristobalite, quartz or flint
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/38—Non-oxide ceramic constituents or additives
- C04B2235/3817—Carbides
- C04B2235/3826—Silicon carbides
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/38—Non-oxide ceramic constituents or additives
- C04B2235/3852—Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
- C04B2235/3856—Carbonitrides, e.g. titanium carbonitride, zirconium carbonitride
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/38—Non-oxide ceramic constituents or additives
- C04B2235/3852—Nitrides, e.g. oxynitrides, carbonitrides, oxycarbonitrides, lithium nitride, magnesium nitride
- C04B2235/3886—Refractory metal nitrides, e.g. vanadium nitride, tungsten nitride
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/38—Non-oxide ceramic constituents or additives
- C04B2235/3895—Non-oxides with a defined oxygen content, e.g. SiOC, TiON
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/44—Metal salt constituents or additives chosen for the nature of the anions, e.g. hydrides or acetylacetonate
- C04B2235/441—Alkoxides, e.g. methoxide, tert-butoxide
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/30—Constituents and secondary phases not being of a fibrous nature
- C04B2235/46—Gases other than oxygen used as reactant, e.g. nitrogen used to make a nitride phase
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
- C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
- C04B2235/52—Constituents or additives characterised by their shapes
- C04B2235/5284—Hollow fibers, e.g. nanotubes
- C04B2235/5288—Carbon nanotubes
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/60—Aspects relating to the preparation, properties or mechanical treatment of green bodies or pre-forms
- C04B2235/606—Drying
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/60—Aspects relating to the preparation, properties or mechanical treatment of green bodies or pre-forms
- C04B2235/616—Liquid infiltration of green bodies or pre-forms
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/65—Aspects relating to heat treatments of ceramic bodies such as green ceramics or pre-sintered ceramics, e.g. burning, sintering or melting processes
- C04B2235/652—Reduction treatment
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/74—Physical characteristics
- C04B2235/77—Density
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
- C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
- C04B2235/80—Phases present in the sintered or melt-cast ceramic products other than the main phase
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/13—Energy storage using capacitors
Definitions
- the present invention relates to metal oxide and more particularly to a high surface area, electrically conductive nanocarbon-supported metal oxide.
- Porous metal oxides can be prepared by a number of techniques ranging from sol-gel synthesis to various templating/support methods. These porous metal oxides have shown enhanced catalytic activity, compared to bulk material, but are still limited by surface areas less than 1000 m 2 /g. This is even the case when using high surface area templates such as SBA-15 or MCM-41. Surface areas for the templated metal oxides can be less than 200 m 2 /g. The use of supports, such as carbon nanotubes, also yields surface areas less than 300 m 2 /g. Another issue presented by many porous metal oxides is that their pore structure collapsing at elevated temperatures. For example in titania aerogels, this lack of pore stability results in order of magnitude decreases in surface area under heating. The presence of silica has been shown to provide some stabilization of pores at high temperatures in titania-silica composites. However, the surface area is still significantly decreased under heating.
- Carbon nanotubes possess a number of intrinsic properties that have made them promising materials in the design of composite materials.
- CNTs can have electrical conductivities as high as 10 6 Sm ⁇ 1 , thermal conductivities as high as 3000 Wm ⁇ 1 K ⁇ 1 , elastic moduli 3 on the order of 1 TPa, and are extremely flexible.
- electrical conductivities as high as 10 6 Sm ⁇ 1
- thermal conductivities as high as 3000 Wm ⁇ 1 K ⁇ 1
- elastic moduli 3 on the order of 1 TPa
- Foams though conductive, tend to be mechanically weak due to their dependence on van der Waals forces for mechanical integrity.
- Nanotechnology is based on the recognition that particles less than the size of 100 nanometers (a nanometer is a billionth of a meter) impart to nanostructures built from them new properties and behavior. This happens because particles which are smaller than the characteristic lengths associated with particular phenomena often display new chemistry and physics, leading to new behavior which depends on the size. So, for example, the electronic structure, conductivity, reactivity, melting temperature, and mechanical properties have all been observed to change when particles become smaller than a critical size.”
- the present invention provides a metal oxide-carbon aerogel composite that includes a carbon aerogel with a metal oxide overcoat.
- the metal oxide-carbon composite is made by providing a carbon aerogel, immersing the carbon aerogel in a metal oxide sol under a vacuum, returning the carbon aerogel with the metal oxide sol to atmospheric pressure, curing the carbon aerogel with the metal oxide sol at room temperature, and drying the carbon aerogel with the metal oxide sol to produce the metal oxide-carbon composite.
- the step of providing a carbon aerogel can be providing an activated carbon aerogel or providing a carbon aerogel with carbon nanotubes that make the carbon aerogel mechanically robust.
- the invention has use as a commercial catalyst.
- the invention also has use as an electrode, for example as an electrode for batteries and super capacitors.
- the invention also has use in water purification, electrical/electrochemical energy storage, solar energy, and hydrogen storage.
- FIGS. 1A and 1B are SEM and TEM images of TiO 2 /SWNT-CA.
- FIG. 2 is a TGA plot of SWNT-CA, TiO 2 /SWNT-CA, and TiO 2 in air.
- FIG. 3 is Semi-log plot of the pore size distribution of the SWNT-CA, TiO 2 /SWNT-CA, and TiO 2 aerogel.
- FIGS. 4A-D are SEM images of TiO 2 /CNT (a,b) and TiCN/CNT (c,d) at different magnifications.
- FIGS. 5A and 5B are TEM images of TiO 2 /CNT and (b) TiCNT/CNT.
- FIGS. 6A-H are SEM images of ACA (a,b), as-prepared TiO 2 /ACA (c,d), heat-treated TiO 2 /ACA (e,f), and TiCN/ACA (g,h) at different magnifications. Arrows indicate particles of amorphous (d), crystalline TiO 2 (f), and TiCN (h).
- FIGS. 7A-C are transmission electron microscopy images of as-prepared TiO 2 /ACA (a), heat-treated TiO 2 /ACA (b), and TiCN/ACA (c).
- FIGS. 5A-D are SEM images of as-prepared SiO 2 /ACA and SiC/ACA.
- FIG. 9 is a flow chart showing one embodiment of a method of making a metal oxide-carbon composite with carbon nanotubes that make said metal oxide-carbon composite mechanically robust.
- FIG. 10 is a flow chart showing one embodiment of a method of making an metal oxide-carbon composite with an activated carbon aerogel.
- the present invention provides a metal oxide-carbon composite that includes a carbon aerogel with an oxide overcoat.
- the metal oxide-carbon composite is made by providing a carbon aerogel, immersing the carbon aerogel in a metal oxide sol under a vacuum, returning the carbon aerogel with the metal oxide sol to atmospheric pressure, curing the carbon aerogel with the metal oxide sol-gel at room temperature to produce the metal oxide-carbon wet gel composite, and drying the metal oxide-carbon wet gel composite to produce the metal oxide-carbon aerogel composite.
- the step of providing a carbon aerogel can be providing an activated carbon aerogel or providing a carbon aerogel with carbon nanotubes that make the carbon aerogel mechanically robust. Apparatus and method of providing an aerogel and a metal oxide are described in U.S. Pat. No.
- CA-CNT Carbon Aerogel & Carbon Nanotube Composite
- SDBS Sodium Dodecylbenzene Sulfonate
- MESOPORPOUS Pore Dia. 2-50 nm
- PVA Polyvinyl Alcohol
- Ultralow-Density Exhibits densities less than 50 mg/cc
- Carbon Nanotube-Based Aerogel Porous carbon material consisting of 5 to 95% carbon nanotubes by weight
- the present invention provides a method of making a metal oxide-carbon composite, comprising the steps of providing an aqueous media or other media to form a suspension, adding reactants and catalyst to said suspension to create a reaction mixture, curing said reaction mixture to form a wet gel, drying said wet gel to produce a dry gel, pyrolyzing said dry gel to produce an aerogel, immerse said aerogel in a metal oxide sol under a vacuum, returning said aerogel and said metal oxide sol to atmospheric pressure, curing said aerogel at room temperature, and drying said aerogel producing an aerogel oxide composite.
- the metal oxide-carbon composite comprises a carbon aerogel, said carbon aerogel having inner surfaces, and an oxide coating said inner surfaces of said carbon aerogel providing an aerogel oxide composite.
- the carbon aerogel is a carbon aerogel with carbon nanotubes that make said carbon aerogel mechanically robust.
- the carbon aerogel is an activated carbon aerogel.
- the oxide is titanium oxide.
- the oxide is an oxide from transitional metal oxide made with forming precursors of manganese or iron or cobalt or nickel or copper or zinc or zirconium or tin salts or alkoxides.
- the present invention provides the fabrication of new nanocarbon-supported titanium dioxide structures that exhibit high surface area and improved electrical conductivity.
- Nanocarbons consisting of single-walled carbon nanotubes and carbon aerogel nanoparticles were used to support titanium dioxide particles and produce monoliths with densities as low as 80 mg/cm 3 .
- the electrical conductivity of the nanocarbon-supported titanium dioxide was dictated by the conductivity of the nanocarbon support while the pore structure was dominated by the titanium dioxide aerogel particles.
- the conductivity of the monoliths presented here was 72 S/m and the surface area was 203 m 2 /g.
- Titanium dioxide is a widely researched material with applications ranging from photocatalysts to electrodes to hydrogen storage materials.
- issues such as absorption limited to the ultraviolet range, high rates of electron-hole recombination, and relatively low surface areas have limited commercial use of titanium dioxide.
- Recent efforts have focused on combining titanium dioxide with various materials to address some of these issues.
- Titanium dioxide in the presence of carbon e.g. carbon nanotubes (CNT)
- CNT carbon nanotubes
- Applicants present the synthesis and characterization of such a high-surface area, conductive TiO 2 /CNT composite.
- Applicants recently reported the synthesis of a novel CNT-based foam, consisting of bundles of single-walled nanotubes (SWNT) crosslinked by carbon aerogel (CA) nanoparticles, which would serve as an excellent candidate for the CNT scaffold of the TiO 2 /CNT composite.
- SWNT-CA foams simultaneously exhibited increased stiffness, and high electrical conductivity even at densities approaching 10 mg cm ⁇ 3 without reinforcement.
- the foams are stable to temperatures approaching 1000° C. and have been shown to be unaltered by exposure to extremely low temperatures during immersion in cryogenic liquids.
- these ultralight, robust foams could allow the formation of novel CNT composites.
- the conductive network As the conductive network is already established, it can be impregnated through the wicking process with a matrix of choice, ranging from inorganic sols to polymer melts to ceramic pastes.
- a variety of conductive CNT composites could be created using the SWNT-CA foam as a pre-made CNT scaffold.
- Applicants use the SWNT-CA as a scaffold for the synthesis of conductive, high surface area TiO 2 /CNT composites.
- SWNT-CA preparation The SWNT-CAs were prepared as described in previous work. Briefly, in a typical reaction, purified SWNTs (Carbon Solutions, Inc.) were suspended in deionized water and thoroughly dispersed using a VWR Scientific Model 75T Aquasonic (sonic power ⁇ 90 W, frequency ⁇ 40 kHz). The concentration of SWNTs in the reaction mixture was 0.7 wt %. Once the SWNTs were dispersed, resorcinol (1.235 g, 11.2 mmol), formaldehyde (1.791 g, 22.1 mmol) and sodium carbonate catalyst (5.95 mg, 0.056 mmol) were added to the reaction solution. The resorcinol to catalyst ratios (R/C) employed was 200.
- the amount of resorcinol and formaldehyde (RF solids) used was 4 wt %.
- the sol-gel mixture was then transferred to glass molds, sealed and cured in an oven at 85° C. for 72 h.
- the resulting gels were then removed from the molds and washed with acetone for 72 h to remove all the water from the pores of the gel network.
- the wet gels were subsequently dried with supercritical CO2 and pyrolyzed at 1050° C. under a N2 atmosphere for 3 h.
- the SWNT-CAs materials were isolated as black cylindrical monoliths. Foams with SWNT loadings of 30 wt % (0.5 vol %) were prepared by this method.
- TiO 2 /SWNT-CA composite preparation Sol-gel chemistry was used to deposit the TiO 2 aerogel layer on the inner surfaces of the SWNT-CA support.
- the TiO 2 sol-gel solution was prepared as described in previous work, In a typical synthesis, SWNT-CA parts were immersed in the TiO 2 sol-gel solution and full infiltration of the SWNT-CA pore network by the sol-gel solution was achieved under vacuum. Following gelation of the titania network, the wet composite was dried using supercritical CO 2 , yielding the TiO 2 /SWNT-CA composite.
- Thermogravimetric analysis was performed on a Shimadzu TGA 50 Thermogravimetric Analyzer to determine TiO 2 content. Samples were heated in flowing air at 10 seem to 1000° C. at 10° C. min in alumina boats. The weight fraction of material remaining was assumed to be pure stoichiometric TiO 2 . Energy dispersive spectroscopy confirmed that only TiO 2 remained after TGA was performed. Surface area determination and pore volume and size analysis were performed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods using an ASAP 2000 Surface Area Analyzer (Micromeritics Instrument Corporation). Samples of approximately 0.1 g were heated to 300° C.
- BET Brunauer-Emmett-Teller
- BJH Barrett-Joyner-Halenda
- the microstructure of the TiO 2 /SWNT-CA composites was examined using SEM and TEM. As shown in FIG. 1A and FIG. 1B , the network structure of the TiO 2 /SWNT-CA composites is similar to that observed in pristine SWNT-CA. The presence of the TiO 2 aerogel layer on the surface of the nanotube bundles can be seen in TEM image. Interestingly, the TiO 2 aerogel appears to have formed primarily on the surfaces of the nanotube bundles despite the fact that the TiO 2 sol-gel solution filled the entire pore volume of the support. The open pore volume in the TiO 2 /SWNT-CA composite is only sparsely populated with TiO 2 particles. This observation indicates that nucleation of the TiO 2 particles during the sol-gel reaction preferentially occurs at the surface of the nanotube bundles.
- Thermal gravimetric analysis in air was used to determine the TiO 2 content in the as-TiO 2 /SWNT-CA composites as illustrated in FIG. 2 .
- combustion of the pristine SWNT-CA occurs around 500° C. and the material is completely consumed by 600° C.
- the 5 wt % remaining is likely metal catalyst from the CNTs.
- the titania exhibits an initial mass loss generally attributed to moisture and organics below 300° C. and is stable thereafter.
- the TGA plot for TiO 2 /SWNT-CA material is a composite of the plots for titania and the SWNT-CA.
- FIG. 3 plots the pore size distribution of the SWNT-CA, TiO 2 /SWNT-CA composite, and pristine TiO 2 aerogel.
- the BET surface area, electrical conductivity and other physical properties of these materials are summarized in Table I.
- Table I shows that the TiO 2 /SWNT-CA composite has high surface area and electrical conductivity. In fact, the electrical conductivity of the SWNT-CA is not adversely affected by the infiltration of the insulating material.
- the titania aerogel appears to simply coat the SWNT-CA scaffold, the increased surface area suggests that the pore morphology of the titania dominates the overall pore morphology of the composite.
- the novel TiO 2 /SWNT-CA monoliths was prepared by coating the CNT struts within the SWNT-CA scaffold with amorphous sol-gel-derived TiO 2 particles. Given the technological interest in crystalline TiO 2 , work is in progress to convert the amorphous TiO 2 layer to the anatase crystalline phase.
- the conductive network of the SWNT-CA scaffold remained intact after infiltration yielding a composite with a conductivity of 72 S m-l and a surface area of 203 in 2 g”].
- SWNT-CAs were shown to provide the means to create conductive, high-surface area TiO 2 composites.
- the general nature of this method should provide a route for the synthesis of a variety of conductive, high surface area composites with applications in photocatalysts and energy storage.
- transition metal nitrides and carbides have received considerable attention recently as catalysts and catalyst supports. They exhibit high resistance to sintering and poisoning, in addition to catalytic activity for a number of useful reactions. Of particular interest is the fact that these transition metal compounds have been shown to have catalytic activity similar to that of typical noble metal catalysts. Thus, substituting transition metal compounds for noble metals is an attractive option for reducing the cost of catalyst materials. Unfortunately, traditional routes to forming metal nitrides and carbides, such as the carbothermal reduction of metal oxides, yield low surface area materials. To increase the specific surface area of transition metal carbides and nitrides, a number of new synthetic methods have been proposed.
- TiCN/CNT monolithic CNT-supported titanium carbonitride aerogel
- This TiCN/CNT was formed by the carbothermal reduction of a TiO 2 -coated low-density CNT-based foam (TiO 2 /CNT) in flowing nitrogen.
- the CNT-based foam (30 wt % CNT, 30 mg cm ⁇ 3 ) that serves as the support consists of single-walled carbon nanotubes crosslinked by carbon aerogel particles (SWNT-CA), as previously described.
- the SWNT-CA was immersed in a TiO 2 sol under vacuum prior to gelation, similar to the method previously reported for fabricating stiff, conductive polymer/CNT composites.
- the TiO 2 sol was prepared via a two-step sol-gel process involving the acid-catalyzed hydrolysis of titanium tetraethoxide, followed by base-initiated gelation of the TiO 2 species. Briefly, a solution of titanium tetraethoxide (1.0 g, 4.4 mmol) and pure ethanol (4.5 mL) was prepared in an ice bath with vigorous stirring.
- Powder X-ray diffraction (XRD) analysis of the samples was performed with Cu K ⁇ radiation on a Scintag PAD-V X-ray diffractometer. TiO 2 powder was used as a standard. Bulk densities of the monoliths were determined from the physical dimensions and mass of each sample. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) characterization were performed on a JEOL 7401-F at 5-10 keV (20 mA) in SEI mode with a working distance of 2-8 mm. To supplement EDX, thermogravimetric analysis (TGA) was performed on a Shimadzu TGA 50 Thermogravimetric Analyzer. Samples were heated in air to 1000° C.
- TEM Transmission electron microscopy
- Samples for TEM were prepared by pulverizing aerogels above TEM grids. Surface area determination and pore volume and size analysis were performed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods using an ASAP 2000 Surface Area Analyzer (Micromeritics Instrument Corporation). Samples of approximately 0.1 g were heated to 300° C. under vacuum (10 ⁇ 5 Torr) for at least 24 hours to remove all adsorbed species prior to analysis. Electrical conductivity was measured using the four-probe method similar to previous studies. Metal electrodes were attached to the ends of cylindrical samples. The amount of current transmitted through the sample during measurement was 100 mA, and the voltage drop along the sample was measured over distances of 3 to 6 mm.
- FIG. 4C and FIG. 4D show the ligament and pore structure of these materials.
- the TiO 2 /CNT resembles the CNT-based foam except for the coating of amorphous TiO 2 .
- the TEM image of the TiO 2 /CNT, FIG. 2A supports this view.
- the TiCN/CNT also has the same basic structure as the original CNT-based foam except that the ligaments are now decorated with TiCN nanocrystals FIGS. 4B and 4C . This observation suggests that the carbon consumed during the reduction of TiO 2 comes primarily from the carbon aerogel coating the CNT bundles, leaving the CNTs intact.
- the integrity of the CNTs was also confirmed via Raman spectroscopy through observation of the peaks characteristic of CNTs (ESI ⁇ ) in the TiCN/CNT.
- the TEM image, FIG. 2B also shows that the TiCN/CNT ligaments, on average, have smaller diameters than the TiO 2 /CNT. The smaller diameters probably occur as the TiO 2 is reduced and carbon aerogel is consumed in the course of forming the TiCN nanocrystals.
- the TiCN/CNT had a brownish color compared to the jet-black CNT-based foam and TiO 2 /CNT.
- Table II summarizes some basic properties of the TiCN/CNT, as well as the CNT-based foam and the TiO 2 /CNT.
- the density of the TiCN/CNT is significantly reduced compared to the TiO 2 /CNT.
- the monolith experienced 49% mass loss and 28% volume shrinkage, resulting in the 55 mg cm ⁇ 3 final density.
- the electrical conductivity of the TiCN/CNT is diminished compared to the CNT-based foam and TiO 2 /CNT, but still high considering the extremely low bulk density of the TiCN/CNT foam.
- the partial consumption during the heat treatment of the graphitic carbon aerogel particles that crosslink the CNT bundles, is likely the cause of the decreased conductivity.
- Interfacial resistance has been shown to be a dominant factor in the transport properties of CNT composites. The removal or narrowing of the critical conduction pathways between CNT bundles effectively increases the interfacial resistance, leading to a decrease in the bulk conductivity.
- Powder XRD was used to determine what phases were present in the TiCN/CNT.
- XRD patterns of the CNT-based foam and TiO 2 /CNT were also included.
- the largest peaks from the CNT-based foam can be attributed to the (100) and (101) graphite peaks (PDF #41-1487). These peaks are also visible in the pattern from the TiO 2 /CNT.
- the absence of additional peaks in the TiO 2 /CNT pattern supports the earlier suggestion that the TiO 2 coating the CNT ligaments is amorphous.
- the XRD peaks for the TiCN/CNT would indicate the presence of the osbornite crystalline phase of TiCN (PDF #06-642).
- Nitrogen adsorption/desorption analysis was performed to determine surface area, pore volume and average pore size of the TiCN/CNT. All three samples had Type IV nitrogen isotherms (ESI ⁇ ), indicative of the predominantly macroporous nature of the CNT-based foam that serves as the foundation for all the samples.
- the addition of TiO 2 and the conversion to TiCN increased both the surface area and pore volume of the composite foams. Peak pore size increases from 56 nm in the CNT-based foam to 72 nm in the TiO 2 /CNT and TiCN/CNT.
- the TiO 2 /CNT exhibits pore morphology similar to that of an amorphous TiO 2 aerogel, suggesting that the TiO 2 coating the CNT bundles dominates the nitrogen sorption behavior.
- the TiCN/CNT maintains the same general morphology as the TiO 2 /CNT, as evidenced by a similar pore size distribution. However, the surface area and pore volume are increased because of the decreased bulk density and additional porosity due to removal of carbon (in the form of gaseous CO) that occurs during carbothermal reduction. Similar increases in surface area were observed by Berger et al. under similar conditions during the conversion of TiO 2 (rutile) and carbon (furnace black or graphite).
- Nanocomposites of titania and various forms of carbon exhibit a number of enhanced functional properties for catalysis and energy-storage applications.
- titania/carbon (TiO 2 /C) composites have higher photocatalytic activity, improved photoefficiency, and a wider absorption band than titania alone.
- Composites of TiO 2 /C have also been shown to improve the energy and power density of electrochemical cells and enhance the storage capacity and reversibility of hydrogen-storage materials. The efficacy of these composite materials depends mainly on the crystallinity and surface area of the titania species.
- ACA activated carbon aerogel
- TiCN titanium carbonitride
- the amorphous TiO 2 overcoat in the composite can then be converted to either anatase TiO 2 or titanium carbonitride through heat treatment under different conditions.
- the as-prepared. TiO 2 /ACA part was heated in air at 400° C. for 2 hours.
- the as-prepared TiO 2 /ACA part was heated under flowing nitrogen at 1400° C. for 4 hours. In both cases, the heat-treated composite materials exhibit extremely high BET surface areas (>1800 m 2 g ⁇ 1 ) and retain the porous network structure of the monolithic ACA support.
- the microstructures of the titania-ACA composites were evaluated using scanning electron microscopy FIGS. 6A-D and transmission electron microscopy FIGS. 7A-C .
- SEM images of as-prepared TiO 2 /ACA FIGS. 6C-D show the same trabecular structure and texture as observed in the pristine ACA FIGS. 6A-B .
- the presence of the TiO 2 aerogel layer on the surface of the ACA can be seen in images of the as-prepared TiO 2 /ACA composites.
- the TiO 2 aerogel appears to have formed primarily on the surfaces of the ACA despite the fact that the TiO 2 sol-gel solution filled the entire pore volume of the support.
- the open pore volume in the ACA composite is only sparsely populated with TiO 2 particles. This observation indicates that nucleation of the TiO 2 particles during the sol-gel reaction preferentially occurs at the surface of the ACA.
- the texture of the TiO 2 /ACA composite appears to roughen, apparently due to the formation of anatase TiO 2 nanocrystals on the ACA surface FIG. 6E-F and FIG. 7C . Further changes in texture are seen after carbothermal reduction of the surface layer of TiO 2 to TiCN FIG. 6G-H and FIG. 7C .
- cubic TiCN crystals ranging in size from 10 to 100 nm are clearly visible on the ACA surface.
- the continuous nature of the crystalline TiCN layer suggests that the deposited TiO 2 completely coated the entire surface of the ACA support. With the bulk of the TiO 2 deposited at the ACA surface, the number of TiO 2 particles formed in sol filling the free space in the ACA is greatly reduced.
- Thermal gravimetric analysis in air was used to determine the TiO 2 content in the as-prepared and annealed TiO 2 /ACA composites as well as the TiCN content in the TiCN/ACA composite.
- combustion of the pristine ACA begins oxidizing at 400° C. and the material is completely consumed by 600° C.
- the onset of mass loss for the annealed TiO 2 /ACA composite is similar to that of the ACA, but the material retains 20% of its original mass due to the presence of the TiO 2 overcoat Table III.
- the TiCN/ACA composite exhibits a slight weight gain at ⁇ 350° C. prior to combustion of the carbon support.
- the increase in mass can be attributed to oxidation of the TiCN layer (molecular weight of 60-62) to TiO 2 (molecular weight of 80).
- complete oxidation of the ACA support in the TiCN/ACA composite does not occur until 680° C. as compared to 600° C. for the other samples, suggesting that the TiCN completely covers the ACA surface, providing an effective barrier to oxygen diffusion.
- the energy dispersive X-ray spectroscopy (EDX) element mapping of the TiCN/ACA shows an even distribution of Ti, C, and N, consistent with a TiCN layer covering most of the ACA, as observed in the SEM and TEM images. Only after the TiCN is converted to the oxide does combustion of the ACA occur. The remaining 18 wt % TiO 2 from combustion of the TiCN/ACA composite implies a starting TiCN content of 14 wt %.
- Powder XRD was used to determine the crystalline phases of the heat-treated TiO 2 /ACA and TiCN/ACA composites. For comparison, the XRD pattern of the ACA was also included.
- the XRD pattern for the as-prepared TiO 2 /ACA (no heat treatment) was very similar to that of the ACA, likely due to the amorphous nature of the titania, and is, therefore, not shown.
- the largest peaks in the diffraction pattern for the ACA material can be attributed to the (100) and (101) graphite peaks (PDF #41-1487). These peaks are also visible in the diffraction patterns for the heat-treated TiO 2 /ACA and TiCN/ACA composites due to the presence of the ACA support.
- the remaining peaks in the XRD pattern for the annealed TiO 2 /ACA composite can be indexed to the anatase phase of TiO 2 (PDF #21-1272). Analysis of the peaks using the Scherrer equation indicates the average crystallite size is ⁇ 9 nm, in agreement with the small size of the crystals observed by electron microscopy.
- the XRD peaks for the TiCN/ACA composite indicate the presence of the osbornite crystalline phase of TiCN (PDF #06-0642) on the ACA support.
- the high nitrogen content is consistent with EDX results showing a Ti:N ratio of close to one.
- the average crystallites size calculated from the XRD data ( ⁇ 20 nm) correlates with the size range of the cubic crystals observed in SEM and TEM analysis. Therefore, based on the XRD data, the heat-treated TiO 2 /ACA composite contained purely anatase nanocrystals, and full reduction of TiO 2 to TiCN was achieved in the TiCN/ACA composite to create a highly nitrogen-enriched layer of TiCN nanocrystals on the ACA surface.
- the textural properties of the TiO 2 /ACA and TiCN/ACA composites were evaluated using nitrogen adsorption/desorption analysis Table III. For comparison, data for the ACA and TiO 2 aerogel (before and after heat treatment) are also included in Table III. Nitrogen adsorption/desorption plots for the ACA and the composites. Each of the composites exhibited type II nitrogen isotherms, indicating a mostly macroporous ( ⁇ 2 nm) material with the remaining pore volume primarily in the large meso- and macropore (>90 nm) range. Coating of the ACA framework with TiO 2 clearly results in a significant decrease in BET surface area (1507 m 2 g ⁇ 1 ) relative to the uncoated ACA.
- the surface area of the as-prepared TiO 2 /ACA composite represents almost an order of magnitude improvement over that of the as-prepared TiO 2 aerogel. Retention of such a large BET surface area in the coated material suggests that the ACA is less susceptible to the negative effects of pore-plugging observed in other scaffold materials, such as activated carbons. Additionally, heat treatment of the as-prepared TiO 2 /ACA leads to a 36% increase in surface area in the annealed composite (2054 m 2 g ⁇ 1 ). This observation is in contrast to the sharp decrease in surface area that occurs upon annealing of the bulk TiO 2 aerogel prepared without the scaffold.
- the increased surface area and pore volume in the annealed composite indicate that the ACA support prevents coarsening and collapse of the TiO 2 coating during heat treatment, even as the amorphous titania is converted to the anatase phase.
- the presence of high-surface area SiO 2 has been shown to have similar effects on the temperature stability of pores in TiO 2 gels.
- correspondingly lower density of the annealed TiO 2 /ACA is consistent with a lack of pore collapse and likely contributes to the observed textural properties.
- the TiCN/ACA composite also exhibits increased surface area and pore volume relative to the as-prepared TiO 2 /ACA composite Table III.
- the increased surface area can be attributed to the additional porosity created by the removal of carbon from the ACA support (in the form of gaseous CO) that occurs during carbothermal reduction. Similar increases in surface area have been reported under similar conditions during the conversion of TiO 2 (rutile) and carbon (furnace black or graphite) mixtures to TiCN. While the surface area and pore volume for the TiCN/ACA composite are slightly lower than those of the heat-treated TiO 2 /ACA, the textural properties are still quite close to those of the original ACA. This observation demonstrates the flexibility of the ACA scaffold for creating a variety of high surface area oxide, carbide and nitride materials.
- titanium(IV) ethoxide (1 g, 0.0125 mol) and ethanol (3.57 g, 0.0776 mol), hydrochloric acid (71.4 ⁇ l), and water (851 ⁇ l) were mixed in an ice bath, followed by the addition of propylene oxide (0.357 g, 0.00616 mol) to prepare the titania sol.
- An activated carbon aerogel monolith was immersed in the titania sol in a glass vial and held under vacuum to ensure full penetration of the sol in the carbon aerogel. The reaction mixture was then cured at room temperature for 24 h.
- the wet composite was washed in ethanol and dried by supercritical extraction in CO 2 to yield the TiO 2 /ACA composite.
- Annealing the as-prepared TiO 2 /ACA composite in air at 400° C. for 2 h was required to convert the amorphous titania layer on the ACA to the anatase phase.
- heating the as-prepared TiO 2 /ACA composite in flowing nitrogen at 1400° C. for 4 h produced the TiCN/ACA composite.
- Powder X-ray diffraction (XRD) analysis of the samples was performed with Cu K ⁇ radiation on a Scintag PAD-V X-ray diffractometer.
- TiO 2 (anatase) powder was used as a standard.
- Bulk densities of the monoliths were determined from the physical dimensions and mass of each sample.
- Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) characterization was performed on a JEOL 7401-F at 5-10 keV (20 mA) in SEI mode with a working distance of 2-8 mm.
- Transmission electron microscopy (TEM) characterization was performed on a JEOL JEM-200CX electron microscope operated at 200 kV.
- Thermogravimetric analysis was performed on a Shimadzu TGA 50 thermogravimetric analyzer to determine TiO 2 and TiCN contents. Samples were heated in flowing air at 10 sccm to 1000° C. at 10° C. min ⁇ 1 in alumina boats. The weight fraction of material remaining was assumed to be pure stoichiometric TiO 2 . The TiCN content of the TiCN/ACA was calculated from the weight fraction of TiO 2 remaining after heating to 1000° C. in air assuming full oxidation of initial TiCN content. Energy dispersive spectroscopy confirmed that only TiO 2 remained after TGA was performed.
- the synthesis and characterization of high surface area carbon-supported silica and silicon carbide aerogels are described.
- An activated carbon aerogel with surface area greater than 3000 m 2 /g was used to as a support for the sol-gel deposition of silica.
- the resulting silica-coated carbon aerogel retained a surface area greater than 2000 m 2 /g and showed improved thermal stability in air.
- the carbon-supported silicon carbide aerogel was made by the carbothermal reduction of the silica-coated carbon aerogel under flowing Ar at 1500° C.
- the resulting monolith maintained a surface area greater than 2000 m 2 /g and was stable to temperatures approaching 600° C., over 100° C. higher than that of the pristine carbon aerogel.
- FIGS. 8A and 8B The microstructures of the silica-ACA composites were evaluated using scanning electron microscopy FIGS. 8A and 8B .
- FIGS. 8A and 8B show the same trabecular structure and texture as observed in the pristine ACA.
- the presence of the SiO 2 aerogel layer on the surface of the ACA can be seen in images of the as-prepared SiO 2 /ACA composites.
- the SiO 2 aerogel appears to have formed primarily on the surfaces of the ACA despite the fact that the SiO 2 sol-gel solution filled the entire pore volume of the support.
- the open pore volume in the ACA composite is only sparsely populated with SiO 2 particles.
- Powder XRD was used to confirm the presence of SiC in the SiC/ACA composite.
- the XRD pattern of the as-prepared SiO 2 /ACA was also included.
- the XRD pattern for the pristine ACA is identical to that of the SiO 2 /ACA, due to the amorphous nature of the as-prepared silica, and is, therefore, not shown.
- the largest peaks in the diffraction pattern for the SiO 2 /ACA material can be attributed to the (100) and (101) graphite peaks. These peaks are also visible in the diffraction pattern for the SiC/ACA composites due to the presence of the ACA support.
- the remaining peaks in the XRD pattern for the SiC/ACA composite can be indexed to moissanite SiC.
- Thermal gravimetric analysis in air was used to determine the thermal stability of the SiO 2 /ACA and SiC/ACA, as well as the SiO 2 and SiC content.
- combustion of the pristine ACA begins at 400° C. and the material is completely consumed by 600° C.
- the mass loss event below 200° C. for the SiO 2 /ACA is due to organic impurities from the as-prepared SiO 2 .
- the onset of ACA mass loss for the SiO 2 /ACA composite is ⁇ 100° C. higher than that of the pristine ACA, suggesting that the SiO 2 covers the ACA surface fairly well and forms a decent barrier to oxygen diffusion. Similar improvements in thermal stability were noted with a TiCN/ACA.
- trimethoxysilane (IV) ethoxide (4.1 g) and methanol (14 g), ammonium hydroxide (200 ml), and water (1.5 g) were mixed to prepare the silica sol.
- An activated carbon aerogel monolith was immersed in the silica sol in a glass vial and held under vacuum to ensure full penetration of the sol in the carbon aerogel.
- the reaction mixture was then cured at room temperature for 24 h.
- the wet composite was washed in ethanol and dried by supercritical extraction in CO 2 to yield the SiO 2 /ACA composite. Heating the as-prepared SiO 2 /ACA composite in flowing argon at 1500° C. for 5 h produced the SiC/ACA composite.
- Powder x-ray diffraction (XRD) analysis of the samples was performed with Cu K a radiation on a Scintag PAD-V X-ray diffractometer.
- TiO 2 (anatase) powder was used as a standard.
- Bulk densities of the monoliths were determined from the physical dimensions and mass of each sample.
- Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) characterization was performed on a JEOL 7401-F at 5-10 keV (20 mA) in SEI mode with a working distance of 2-8 mm.
- Transmission electron microscopy (TEM) characterization was performed on a JEOL JEM-200CX Electron Microscope operated at 200 kV.
- Thermogravimetric analysis was performed on a Shimadzu TGA 50 Thermogravimetric Analyzer to determine SiO 2 and SiC content. Samples were heated in flowing air at 10 sccm to 1000° C. at 10° C./min in alumina boats. The weight fraction of material remaining was assumed to be pure stoichiometric SiO 2 and SiC. Surface area determination and pore volume analysis were performed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods using an ASAP 2000 Surface Area Analyzer (Micromeritics Instrument Corporation). 42 Samples of approximately 0.1 g were heated to 300° C. under vacuum (10 ⁇ 5 Torr) for at least 24 h to remove all adsorbed species, prior to analysis.
- BET Brunauer-Emmett-Teller
- BJH Barrett-Joyner-Halenda
- the method 900 includes a number of steps.
- the steps include dispersing nanotubes in an aqueous media or other media to form a suspension, adding reactants and catalyst to the suspension to create a reaction mixture, curing the reaction mixture to form a wet gel, drying the wet gel to produce a dry gel, pyrolyzing the dry gel to produce a carbon nanotube-based aerogel, immerse the carbon nanotube-based aerogel in a metal oxide sol under a vacuum, returning the carbon nanotube-based aerogel and the metal oxide sol to atmospheric pressure, curing the metal oxide-carbon nanotube-based composite at room temperature, and drying the metal oxide-carbon nanotube-based wet gel composite producing an metal oxide-carbon composite.
- the step of immersing the carbon nanotube-based aerogel in a metal oxide sol under a vacuum comprises immersing the carbon nanotube-based aerogel in titanium dioxide. In one embodiment the step of immersing the carbon nanotube-based aerogel in a metal oxide sol under a vacuum comprises immersing the carbon nanotube-based aerogel in a metal oxide sol made from Mn, Fe, Co, Ni, Cu, Sn, Al, Si, Zn, Zr sol-gel precursors in combination with catalyst, and sol-gel forming components.
- the method 900 includes a number of steps. The steps shown include the steps described below.
- Step number 901 is “Obtain resorcinol, form-aldehyde, sodium carbonate, sodium dodecylbenzene sulfonate (SDBS) and purified double-walled nanotubes (DWNT).”
- Step number 902 is “Purified DWNTS suspended in aqueous solution containing SDBS.”
- Step number 903 is “Dispersal of DWNTS in aqueous surfactant solution containing SDBS using soniction.”
- Step number 904 is “Resorcinol, formaldehyde and sodium carbonate catalyst added to the reaction solution.”
- Step number 905 is “Sol-Gel mixture transferred to glass molds sealed and cured in oven at 85° C. for 72 hours.”
- Step number 906 is “Resulting gel removed from mold and washed with acetone for 72 hours to remove all water from pores of gel network.”
- Step number 907 is “Wet gel dried with supercritical CO 2 and pyrolyzed at 1050° C. under N 2 atmosphere for 3 hours.”
- Step number 908 is “Resulting composite material (CA-DWNT) isolated as black cylinder monoliths.”
- Step number 909 is “Immerse in titanium dioxide (Ti 0 2 ) sol: infiltration of pore network achieved under vacuum.”
- Step number 910 is “Return to atmospheric pressure and dry wet composite using supercritical CO 2 producing a metal oxide-carbon composite.
- the method 1000 includes a number of steps. The steps include providing an aqueous media or other media to form a suspension, adding reactants and catalyst to the suspension to create a reaction mixture, curing the reaction mixture to form a wet gel, drying the wet gel to produce a dry gel, pyrolyzing the dry gel to produce an aerogel, immerse the aerogel in a metal oxide sol under a vacuum, returning the aerogel and the metal oxide sol to atmospheric pressure, curing the metal oxide sol-infiltrated carbon aerogel, and drying the metal oxide-carbon wet gel composite producing a metal oxide-carbon aerogel composite.
- the step of immersing the carbon aerogel in a metal oxide sol under a vacuum comprises immersing the carbon aerogel in titanium dioxide sol. In one embodiment the step of immersing the carbon aerogel in a metal oxide sol under a vacuum comprises immersing the carbon aerogel in a metal oxide sol made from Mn, Fe, Co, Ni, Cu, Zn, Zr sol-gel precursors in combination with a catalyst, and sol-gel forming components.
- the method 1000 includes a number of steps. The steps shown include the steps described below.
- Step number 1001 is “Resorcinol and 37% formaldehyde solution dissolved in water.”
- Step number 1002 is “Add glacial acetic acid.”
- Step number 1003 is “Transferred to glass molds and cured at 80° C. for 72 hours.”
- Step number 1004 is “Resultant organic hydrogels washed with acetone to remove water and dried with supercritical C0 2 .”
- Step number 1005 is “Organic aerogels carbonized at 1050° C. for 3 hours under N 2 atmosphere.”
- Step number 1006 is “Carbon monoliths.”
- Step number 1007 is “Activating carbon aerogel by exposing to stream of CO 2 at 950° for different soak times.”
- Step number 1008 is “Shorter activation time new porosity is in the form of micropores.”
- Step number 1009 is “Longer activation time. The micropore are widened to sizes that cross the micropore mesopore boundry.”
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Ceramic Engineering (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Power Engineering (AREA)
- Inorganic Chemistry (AREA)
- Nanotechnology (AREA)
- Structural Engineering (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- Composite Materials (AREA)
- Crystallography & Structural Chemistry (AREA)
- Thermal Sciences (AREA)
- General Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- Dispersion Chemistry (AREA)
- Carbon And Carbon Compounds (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Abstract
Description
- The present application claims benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/147,805 filed Jan. 28, 2009 entitled “High Surface Area, Electrically Conductive Nanocarbon-Supported Metal Oxide,” the disclosure of which is hereby incorporated by reference in its entirety for all purposes.
- The United States Government has rights in this invention pursuant to Contract No. DE-AC52-07NA27344 between the United States Department of Energy and Lawrence Livermore National Security, LLC for the operation of Lawrence Livermore National Laboratory.
- 1. Field of Endeavor
- The present invention relates to metal oxide and more particularly to a high surface area, electrically conductive nanocarbon-supported metal oxide.
- 2. State of Technology
- Porous metal oxides can be prepared by a number of techniques ranging from sol-gel synthesis to various templating/support methods. These porous metal oxides have shown enhanced catalytic activity, compared to bulk material, but are still limited by surface areas less than 1000 m2/g. This is even the case when using high surface area templates such as SBA-15 or MCM-41. Surface areas for the templated metal oxides can be less than 200 m2/g. The use of supports, such as carbon nanotubes, also yields surface areas less than 300 m2/g. Another issue presented by many porous metal oxides is that their pore structure collapsing at elevated temperatures. For example in titania aerogels, this lack of pore stability results in order of magnitude decreases in surface area under heating. The presence of silica has been shown to provide some stabilization of pores at high temperatures in titania-silica composites. However, the surface area is still significantly decreased under heating.
- Carbon nanotubes (CNTs) possess a number of intrinsic properties that have made them promising materials in the design of composite materials. CNTs can have electrical conductivities as high as 106 Sm−1, thermal conductivities as high as 3000 Wm−1K−1, elastic moduli3 on the order of 1 TPa, and are extremely flexible. Unfortunately, the realization of these properties in macroscopic forms such as foams and composites has been limited. Foams, though conductive, tend to be mechanically weak due to their dependence on van der Waals forces for mechanical integrity.
- The treatise, Introduction to Nanotechnology, by Charles P. Poole, Jr., and Frank J. Owens. John Wiley &. Sons, 2003, states: “Nanotechnology is based on the recognition that particles less than the size of 100 nanometers (a nanometer is a billionth of a meter) impart to nanostructures built from them new properties and behavior. This happens because particles which are smaller than the characteristic lengths associated with particular phenomena often display new chemistry and physics, leading to new behavior which depends on the size. So, for example, the electronic structure, conductivity, reactivity, melting temperature, and mechanical properties have all been observed to change when particles become smaller than a critical size.”
- Features and advantages of the present invention will become apparent from the following description. Applicants are providing this description, which includes drawings and examples of specific embodiments, to give a broad representation of the invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this description and by practice of the invention. The scope of the invention is not intended to be limited to the particular forms disclosed and the invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
- The present invention provides a metal oxide-carbon aerogel composite that includes a carbon aerogel with a metal oxide overcoat. The metal oxide-carbon composite is made by providing a carbon aerogel, immersing the carbon aerogel in a metal oxide sol under a vacuum, returning the carbon aerogel with the metal oxide sol to atmospheric pressure, curing the carbon aerogel with the metal oxide sol at room temperature, and drying the carbon aerogel with the metal oxide sol to produce the metal oxide-carbon composite. The step of providing a carbon aerogel can be providing an activated carbon aerogel or providing a carbon aerogel with carbon nanotubes that make the carbon aerogel mechanically robust.
- The invention has use as a commercial catalyst. The invention also has use as an electrode, for example as an electrode for batteries and super capacitors. The invention also has use in water purification, electrical/electrochemical energy storage, solar energy, and hydrogen storage.
- The invention is susceptible to modifications and alternative forms. Specific embodiments are shown by way of example. It is to be understood that the invention is not limited to the particular forms disclosed. The invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
- The accompanying drawings, which are incorporated into and constitute a part of the specification, illustrate specific embodiments of the invention and, together with the general description of the invention given above, and the detailed description of the specific embodiments, serve to explain the principles of the invention.
-
FIGS. 1A and 1B are SEM and TEM images of TiO2/SWNT-CA. -
FIG. 2 is a TGA plot of SWNT-CA, TiO2/SWNT-CA, and TiO2 in air. -
FIG. 3 is Semi-log plot of the pore size distribution of the SWNT-CA, TiO2/SWNT-CA, and TiO2 aerogel. -
FIGS. 4A-D are SEM images of TiO2/CNT (a,b) and TiCN/CNT (c,d) at different magnifications. -
FIGS. 5A and 5B are TEM images of TiO2/CNT and (b) TiCNT/CNT. -
FIGS. 6A-H are SEM images of ACA (a,b), as-prepared TiO2/ACA (c,d), heat-treated TiO2/ACA (e,f), and TiCN/ACA (g,h) at different magnifications. Arrows indicate particles of amorphous (d), crystalline TiO2 (f), and TiCN (h). -
FIGS. 7A-C are transmission electron microscopy images of as-prepared TiO2/ACA (a), heat-treated TiO2/ACA (b), and TiCN/ACA (c). -
FIGS. 5A-D are SEM images of as-prepared SiO2/ACA and SiC/ACA. -
FIG. 9 is a flow chart showing one embodiment of a method of making a metal oxide-carbon composite with carbon nanotubes that make said metal oxide-carbon composite mechanically robust. -
FIG. 10 is a flow chart showing one embodiment of a method of making an metal oxide-carbon composite with an activated carbon aerogel. - Referring to the drawings, to the following detailed description, and to incorporated materials, detailed information about the invention is provided including the description of specific embodiments. The detailed description serves to explain the principles of the invention. The invention is susceptible to modifications and alternative forms. The invention is not limited to the particular forms disclosed. The invention covers all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
- The present invention provides a metal oxide-carbon composite that includes a carbon aerogel with an oxide overcoat. The metal oxide-carbon composite is made by providing a carbon aerogel, immersing the carbon aerogel in a metal oxide sol under a vacuum, returning the carbon aerogel with the metal oxide sol to atmospheric pressure, curing the carbon aerogel with the metal oxide sol-gel at room temperature to produce the metal oxide-carbon wet gel composite, and drying the metal oxide-carbon wet gel composite to produce the metal oxide-carbon aerogel composite. The step of providing a carbon aerogel can be providing an activated carbon aerogel or providing a carbon aerogel with carbon nanotubes that make the carbon aerogel mechanically robust. Apparatus and method of providing an aerogel and a metal oxide are described in U.S. Pat. No. 6,986,818, U.S. Pat. No. 7,270,851; U.S. Pat. No. 7,410,718; U.S. Published Patent Application No. 20090123358; Published Patent Application No. 20090229032; and Published Patent Application No. 20090317619. U.S. Pat. No. 6,986,818, U.S. Pat. No. 7,270,851; U.S. Pat. No. 7,410,718; U.S. Published Patent Application No. 20090123358; Published Patent Application No. 20090229032; and Published Patent Application No. 20090317619 are incorporated herein in their entirety by this reference for all purposes.
- Various terms used in this patent application are defined below.
- CA=Carbon Aerogel
- CNT=Carbon Nanotubes
- CA-CNT=Carbon Aerogel & Carbon Nanotube Composite
- SWNT=Single-Walled Carbon Nanotubes
- DWNT=Double-Walled Carbon Nanotubes
- SDBS=Sodium Dodecylbenzene Sulfonate
- MESOPORPOUS=Pore Dia. 2-50 nm
- PVA=Polyvinyl Alcohol
- CVD=Chemical Vapor Deposition
- TEM=Transmission Electron Microscopy
- SEM=Scanning Electron Microscopy
- R/C=Resorcinol to Catalyst Ratios
- RF=Resorcinol and Formaldehyde Solids
- BET=Brunauer-Emmett-Teller
- Mechanically Robust=Can withstand strains greater than 10% before fracture
- Electrically Conductive=Exhibits an electrical conductivity of 10 S/m or greater
- Ultralow-Density=Exhibits densities less than 50 mg/cc
- Carbon Nanotube-Based Aerogel=Porous carbon material consisting of 5 to 95% carbon nanotubes by weight
- The present invention provides a method of making a metal oxide-carbon composite, comprising the steps of providing an aqueous media or other media to form a suspension, adding reactants and catalyst to said suspension to create a reaction mixture, curing said reaction mixture to form a wet gel, drying said wet gel to produce a dry gel, pyrolyzing said dry gel to produce an aerogel, immerse said aerogel in a metal oxide sol under a vacuum, returning said aerogel and said metal oxide sol to atmospheric pressure, curing said aerogel at room temperature, and drying said aerogel producing an aerogel oxide composite. The metal oxide-carbon composite comprises a carbon aerogel, said carbon aerogel having inner surfaces, and an oxide coating said inner surfaces of said carbon aerogel providing an aerogel oxide composite. In one embodiment the carbon aerogel is a carbon aerogel with carbon nanotubes that make said carbon aerogel mechanically robust. In another embodiment the carbon aerogel is an activated carbon aerogel. In one embodiment the oxide is titanium oxide. In another embodiment the oxide is an oxide from transitional metal oxide made with forming precursors of manganese or iron or cobalt or nickel or copper or zinc or zirconium or tin salts or alkoxides.
- The present invention provides the fabrication of new nanocarbon-supported titanium dioxide structures that exhibit high surface area and improved electrical conductivity. Nanocarbons consisting of single-walled carbon nanotubes and carbon aerogel nanoparticles were used to support titanium dioxide particles and produce monoliths with densities as low as 80 mg/cm3. The electrical conductivity of the nanocarbon-supported titanium dioxide was dictated by the conductivity of the nanocarbon support while the pore structure was dominated by the titanium dioxide aerogel particles. The conductivity of the monoliths presented here was 72 S/m and the surface area was 203 m2/g.
- Titanium dioxide is a widely researched material with applications ranging from photocatalysts to electrodes to hydrogen storage materials. However, issues such as absorption limited to the ultraviolet range, high rates of electron-hole recombination, and relatively low surface areas have limited commercial use of titanium dioxide. Recent efforts have focused on combining titanium dioxide with various materials to address some of these issues. Titanium dioxide in the presence of carbon (e.g. carbon nanotubes (CNT)) is currently one of the most attractive combinations. While recent work has shown some improvements, surfaces areas and photocatalytic activity are still limited. Maintaining high surface areas while improving electrical conductivities, one could envision charging-discharging rates and photoefficiencies that are significantly higher than currently possible. Unfortunately for CNT composites, improvements in electrical conductivity are often not fully realized due to poor dispersion of CNTs in the matrix material, impeding the formation of a conductive network. However, with a mechanically robust, electrically conductive CNT foam, one could imagine simply coating this low-density CNT scaffold with titanium dioxide, yielding conductive nanocarbon-supported titanium dioxide.
- Here Applicants present the synthesis and characterization of such a high-surface area, conductive TiO2/CNT composite. Applicants recently reported the synthesis of a novel CNT-based foam, consisting of bundles of single-walled nanotubes (SWNT) crosslinked by carbon aerogel (CA) nanoparticles, which would serve as an excellent candidate for the CNT scaffold of the TiO2/CNT composite. The SWNT-CA foams simultaneously exhibited increased stiffness, and high electrical conductivity even at densities approaching 10 mg cm−3 without reinforcement. The foams are stable to temperatures approaching 1000° C. and have been shown to be unaltered by exposure to extremely low temperatures during immersion in cryogenic liquids. So, in addition to their use in applications such as catalyst supports, sensors, and electrodes, these ultralight, robust foams could allow the formation of novel CNT composites. As the conductive network is already established, it can be impregnated through the wicking process with a matrix of choice, ranging from inorganic sols to polymer melts to ceramic pastes. Thus, a variety of conductive CNT composites could be created using the SWNT-CA foam as a pre-made CNT scaffold. Applicants use the SWNT-CA as a scaffold for the synthesis of conductive, high surface area TiO2/CNT composites.
- Experiment
- Materials. All reagents were used without further purification. Resorcinol (99%) and formaldehyde (37% in water) were purchased from Aldrich Chemical Co. Sodium carbonate (anhydrous) was purchased from J. T. Baker Chemical Co. Highly purified SWNTs were purchased from Carbon Solutions, Inc.
- SWNT-CA preparation. The SWNT-CAs were prepared as described in previous work. Briefly, in a typical reaction, purified SWNTs (Carbon Solutions, Inc.) were suspended in deionized water and thoroughly dispersed using a VWR Scientific Model 75T Aquasonic (sonic power −90 W, frequency −40 kHz). The concentration of SWNTs in the reaction mixture was 0.7 wt %. Once the SWNTs were dispersed, resorcinol (1.235 g, 11.2 mmol), formaldehyde (1.791 g, 22.1 mmol) and sodium carbonate catalyst (5.95 mg, 0.056 mmol) were added to the reaction solution. The resorcinol to catalyst ratios (R/C) employed was 200. The amount of resorcinol and formaldehyde (RF solids) used was 4 wt %. The sol-gel mixture was then transferred to glass molds, sealed and cured in an oven at 85° C. for 72 h. The resulting gels were then removed from the molds and washed with acetone for 72 h to remove all the water from the pores of the gel network. The wet gels were subsequently dried with supercritical CO2 and pyrolyzed at 1050° C. under a N2 atmosphere for 3 h. The SWNT-CAs materials were isolated as black cylindrical monoliths. Foams with SWNT loadings of 30 wt % (0.5 vol %) were prepared by this method.
- TiO2/SWNT-CA composite preparation. Sol-gel chemistry was used to deposit the TiO2 aerogel layer on the inner surfaces of the SWNT-CA support. The TiO2 sol-gel solution was prepared as described in previous work, In a typical synthesis, SWNT-CA parts were immersed in the TiO2 sol-gel solution and full infiltration of the SWNT-CA pore network by the sol-gel solution was achieved under vacuum. Following gelation of the titania network, the wet composite was dried using supercritical CO2, yielding the TiO2/SWNT-CA composite.
- Characterization. Bulk densities of the TiO2/SWNT-CA composites were determined from the physical dimensions and mass of each sample. The volume percent of SWNT in each sample was calculated from the initial mass of SWNTs added, assuming a CNT density of 1.3 g/cm3, and the final volume of the aerogel. Scanning electron microscopy (SEM) characterization was performed on a JEOL 7401-F at 10 keV (20 mA) in SEI mode with a working distance of 2 mm. Transmission electron microscopy (TEM) characterization was performed on a JEOL JEM-200CX. Thermogravimetric analysis (TGA) was performed on a
Shimadzu TGA 50 Thermogravimetric Analyzer to determine TiO2 content. Samples were heated in flowing air at 10 seem to 1000° C. at 10° C. min in alumina boats. The weight fraction of material remaining was assumed to be pure stoichiometric TiO2. Energy dispersive spectroscopy confirmed that only TiO2 remained after TGA was performed. Surface area determination and pore volume and size analysis were performed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods using an ASAP 2000 Surface Area Analyzer (Micromeritics Instrument Corporation). Samples of approximately 0.1 g were heated to 300° C. under vacuum (10 Ton) for at least 24 hours to remove all adsorbed species. Electrical conductivity was measured using the four-probe method similar to previous studies. Metal electrodes were attached to the ends of the cylindrical samples. The amount of current transmitted through the sample during measurement was 100 mA and the voltage drop along the sample was measured over distances of 3 to 6 mm. Seven or more measurements were taken on each sample. - The microstructure of the TiO2/SWNT-CA composites was examined using SEM and TEM. As shown in
FIG. 1A andFIG. 1B , the network structure of the TiO2/SWNT-CA composites is similar to that observed in pristine SWNT-CA. The presence of the TiO2 aerogel layer on the surface of the nanotube bundles can be seen in TEM image. Interestingly, the TiO2 aerogel appears to have formed primarily on the surfaces of the nanotube bundles despite the fact that the TiO2 sol-gel solution filled the entire pore volume of the support. The open pore volume in the TiO2/SWNT-CA composite is only sparsely populated with TiO2 particles. This observation indicates that nucleation of the TiO2 particles during the sol-gel reaction preferentially occurs at the surface of the nanotube bundles. - Thermal gravimetric analysis in air was used to determine the TiO2 content in the as-TiO2/SWNT-CA composites as illustrated in
FIG. 2 . As expected, combustion of the pristine SWNT-CA occurs around 500° C. and the material is completely consumed by 600° C. The 5 wt % remaining is likely metal catalyst from the CNTs. The titania exhibits an initial mass loss generally attributed to moisture and organics below 300° C. and is stable thereafter. Not surprisingly, the TGA plot for TiO2/SWNT-CA material is a composite of the plots for titania and the SWNT-CA. It is interesting to note that the combustion of the SWNT-CA occurs significantly earlier for the TiO2/SWNT-CA compared to that for the pristine SWNT-CA, which may be the result of a catalytic effect of the titania aerogel particles on carbon oxidation. Nevertheless, the nearly 50 wt % remaining after combustion of the SWNT-CA confirm the presence of titania in the TiO2/SWNT-CA composite. -
FIG. 3 plots the pore size distribution of the SWNT-CA, TiO2/SWNT-CA composite, and pristine TiO2 aerogel. The BET surface area, electrical conductivity and other physical properties of these materials are summarized in Table I. Table I shows that the TiO2/SWNT-CA composite has high surface area and electrical conductivity. In fact, the electrical conductivity of the SWNT-CA is not adversely affected by the infiltration of the insulating material. Though, based on the SEM and TEM images (FIG. 1 ), the titania aerogel appears to simply coat the SWNT-CA scaffold, the increased surface area suggests that the pore morphology of the titania dominates the overall pore morphology of the composite. This is confirmed via the pore size distribution, which shows that the pore size distribution of the TiO2/SWNT-CA is much closer to that of pristine TiO2 aerogel than that of the SWNT-CA. Thus, with the TiO2/SWNT-CA composite, a new class of materials with good electrical conductivity and high surface area are realized. -
TABLE 1 Physical properties of SWNT-CA, TiO2/SWNT-CA, and TiO2 aerogel. CNT, vol % Density, SBET, σ, Material (wt %) g/cm3 m2/g Scm−1 SWNT-CA 0.5 (30) 0.030 184 0.77 TiO2/SWNT-CA 0.5 (8) 0.082 203 0.72 TiO2 aerogel 0 (0) 0.193 237 <0.001 - Applicants have described a straightforward method for the fabrication of electrically conductive, high-surface area TiO2/CNT composites. The novel TiO2/SWNT-CA monoliths was prepared by coating the CNT struts within the SWNT-CA scaffold with amorphous sol-gel-derived TiO2 particles. Given the technological interest in crystalline TiO2, work is in progress to convert the amorphous TiO2 layer to the anatase crystalline phase. The conductive network of the SWNT-CA scaffold remained intact after infiltration yielding a composite with a conductivity of 72 S m-l and a surface area of 203 in 2 g”]. Therefore, the SWNT-CAs were shown to provide the means to create conductive, high-surface area TiO2 composites. The general nature of this method should provide a route for the synthesis of a variety of conductive, high surface area composites with applications in photocatalysts and energy storage.
- This nanocarbon-supported titanium dioxide example is described in greater detail in the journal article, “Synthesis and Characterization of Nanocarbon-Supported Titanium Dioxide,” Author(s): Marcus A Worsley, Joshua D. Kuntz, Octavio Cervantes, T Yong-Jin Han, Peter Pauzauskie, Joe H Satcher, Theodore F Baumann, Paper #: 1174-V03-06, DOI: 10.1557/PROC-1174-V03-06, 2010 MRS Spring Meeting, Material Research Society. The journal article “Synthesis and Characterization of Nanocarbon-Supported Titanium Dioxide,” by Marcus A. Worsley, Joshua D. Kuntz, Octavio Cervantes, T. Yong-Jin Han, Peter J. Pauzauskie, Joe H. Satcher, Jr. and Theodore F. Baumann, Mater. Res. Soc. Proc. Vol. 1174, (2009) is incorporated herein in its entirety by this reference for all purposes.
- Porous transition metal nitrides and carbides have received considerable attention recently as catalysts and catalyst supports. They exhibit high resistance to sintering and poisoning, in addition to catalytic activity for a number of useful reactions. Of particular interest is the fact that these transition metal compounds have been shown to have catalytic activity similar to that of typical noble metal catalysts. Thus, substituting transition metal compounds for noble metals is an attractive option for reducing the cost of catalyst materials. Unfortunately, traditional routes to forming metal nitrides and carbides, such as the carbothermal reduction of metal oxides, yield low surface area materials. To increase the specific surface area of transition metal carbides and nitrides, a number of new synthetic methods have been proposed. One promising approach involves the use of high surface area templates or supports to control the microstructure of the transition metal nitride and carbide. For example, both high surface area SiO2 and C3N4 have been used to form TiN powders with surface areas in excess of 100 m2/g. With surface areas as high as 1000 m2/g, carbon nanotubes (CNT) could also serve as such a high surface area support. There have been a number of studies exploring the deposition of various metal oxides on CNTs, however, to our knowledge, only one study examines depositing a transition metal nitride on CNTs. And while the fabrication of metal nitride or carbide nanostructures has received a lot of attention, the use of CNTs for creating high surface area transition metal nitrides or carbides has not been reported.
- Here Applicants report the synthesis and characterization of a monolithic CNT-supported titanium carbonitride aerogel (TiCN/CNT) with surface area in excess of 250 m2/g. This TiCN/CNT was formed by the carbothermal reduction of a TiO2-coated low-density CNT-based foam (TiO2/CNT) in flowing nitrogen. The CNT-based foam (30 wt % CNT, 30 mg cm−3) that serves as the support consists of single-walled carbon nanotubes crosslinked by carbon aerogel particles (SWNT-CA), as previously described. To prepare the TiO2/CNT, the SWNT-CA was immersed in a TiO2 sol under vacuum prior to gelation, similar to the method previously reported for fabricating stiff, conductive polymer/CNT composites. The TiO2 sol was prepared via a two-step sol-gel process involving the acid-catalyzed hydrolysis of titanium tetraethoxide, followed by base-initiated gelation of the TiO2 species. Briefly, a solution of titanium tetraethoxide (1.0 g, 4.4 mmol) and pure ethanol (4.5 mL) was prepared in an ice bath with vigorous stirring. Once chilled, hydrochloric acid (37%, 71.4 μL) and deionized water (85.7 μL) were then added to the titanium tetraethoxide/ethanol solution. After five minutes of continuous stirring, propylene oxide (0.36 g, 6.1 mmol) was finally added to the reaction mixture. The reaction mixture was stirred for another five minutes before immersing the SWNT-CA monolith in the TiO2 sol. Vacuum was applied to the reaction vessel to ensure complete infiltration of the TiO2 sol in the SWNT-CA. After infiltration, the TiO2 sol was then allowed to gel in the SWNT-CA under ambient conditions. The wet composite gel was then dried using supercritical CO2, yielding the TiO2/CNT. The TiO2/CNT was then heated under flowing nitrogen at 1400° C. for 4 hours to yield the TiCN/CNT monolith.
- Powder X-ray diffraction (XRD) analysis of the samples was performed with Cu Kα radiation on a Scintag PAD-V X-ray diffractometer. TiO2 powder was used as a standard. Bulk densities of the monoliths were determined from the physical dimensions and mass of each sample. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) characterization were performed on a JEOL 7401-F at 5-10 keV (20 mA) in SEI mode with a working distance of 2-8 mm. To supplement EDX, thermogravimetric analysis (TGA) was performed on a
Shimadzu TGA 50 Thermogravimetric Analyzer. Samples were heated in air to 1000° C. at 10° C./min in alumina boats. Transmission electron microscopy (TEM) characterization was performed on a JEOL JEM-200CX Electron Microscope operated at 200 kV. Samples for TEM were prepared by pulverizing aerogels above TEM grids. Surface area determination and pore volume and size analysis were performed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods using an ASAP 2000 Surface Area Analyzer (Micromeritics Instrument Corporation). Samples of approximately 0.1 g were heated to 300° C. under vacuum (10−5 Torr) for at least 24 hours to remove all adsorbed species prior to analysis. Electrical conductivity was measured using the four-probe method similar to previous studies. Metal electrodes were attached to the ends of cylindrical samples. The amount of current transmitted through the sample during measurement was 100 mA, and the voltage drop along the sample was measured over distances of 3 to 6 mm. - SEM images of the TiO2/CNT,
FIG. 4A andFIG. 4B and TiCN/CNT)FIG. 4C andFIG. 4D show the ligament and pore structure of these materials. The TiO2/CNT resembles the CNT-based foam except for the coating of amorphous TiO2. The TEM image of the TiO2/CNT,FIG. 2A , supports this view. The TiCN/CNT also has the same basic structure as the original CNT-based foam except that the ligaments are now decorated with TiCN nanocrystalsFIGS. 4B and 4C . This observation suggests that the carbon consumed during the reduction of TiO2 comes primarily from the carbon aerogel coating the CNT bundles, leaving the CNTs intact. The integrity of the CNTs was also confirmed via Raman spectroscopy through observation of the peaks characteristic of CNTs (ESI†) in the TiCN/CNT. The TEM image,FIG. 2B , also shows that the TiCN/CNT ligaments, on average, have smaller diameters than the TiO2/CNT. The smaller diameters probably occur as the TiO2 is reduced and carbon aerogel is consumed in the course of forming the TiCN nanocrystals. The TiCN/CNT had a brownish color compared to the jet-black CNT-based foam and TiO2/CNT. -
TABLE 1I Density (ρ), electrical conductivity (σ), and elemental content (Ti, C, N, O) of the composite foams Material ρ, g cm−3 σ, S cm−1 Ti, at % (wt %) C, at % (wt %) N, at % (wt %) O, at % (wt %) CNT-based foam 0.030 0.77 — 95 (93) — 5.0 (6.6) TiO2/CNT 0.082 0.72 9.4 (28) 71 (53) — 19 (19) TiCN/CNT 0.055 0.25 17 (43) 65 (43) 18 (14) <1 (<1) - Table II summarizes some basic properties of the TiCN/CNT, as well as the CNT-based foam and the TiO2/CNT. The density of the TiCN/CNT is significantly reduced compared to the TiO2/CNT. During the carbothermal reduction, the monolith experienced 49% mass loss and 28% volume shrinkage, resulting in the 55 mg cm−3 final density. The electrical conductivity of the TiCN/CNT is diminished compared to the CNT-based foam and TiO2/CNT, but still high considering the extremely low bulk density of the TiCN/CNT foam. The partial consumption during the heat treatment of the graphitic carbon aerogel particles that crosslink the CNT bundles, is likely the cause of the decreased conductivity. Interfacial resistance has been shown to be a dominant factor in the transport properties of CNT composites. The removal or narrowing of the critical conduction pathways between CNT bundles effectively increases the interfacial resistance, leading to a decrease in the bulk conductivity.
- Elemental analysis by EDX and TGA suggests that the TiO2 in the TiO2/CNT is completely converted to TiCN in the TiCN/CNT. This observation is consistent with literature on the carbothermal reduction of TiO2 under the conditions of this study. Under a constant supply of nitrogen and excess carbon, it is expected that 100% reduction should occur, assuming temperature and time are chosen appropriately. Previous studies have shown 100% reduction at temperatures as low as 1300° C. for a 4 hour hold time. The roughly 1:1 Ti:N ratio suggests a fairly N-rich TiCN phase was formed. EDX elemental mapping (ESI†) shows an even distribution of elements indicative of a TiCN layer that covers most of the CNT surface. XRD analysis offers more details concerning the composition of the TiCN phase.
- Powder XRD was used to determine what phases were present in the TiCN/CNT. For reference, XRD patterns of the CNT-based foam and TiO2/CNT were also included. The largest peaks from the CNT-based foam can be attributed to the (100) and (101) graphite peaks (PDF #41-1487). These peaks are also visible in the pattern from the TiO2/CNT. The absence of additional peaks in the TiO2/CNT pattern supports the earlier suggestion that the TiO2 coating the CNT ligaments is amorphous. The XRD peaks for the TiCN/CNT would indicate the presence of the osbornite crystalline phase of TiCN (PDF #06-642). The calculated lattice parameter, a, for the TiCN/CNT, 4.244 Å, is in good agreement with TiC1-xNx (x=0.95) and very close to the value for pure TiN, 4.240. Peak broadening indicates that the average crystallite size is about 20 nm, consistent with the particle sizes observed in SEM and TEM analysis and. Therefore, based on the XRD data, a highly nitrogen-enriched layer of TiCN nanocrystals covers the CNT bundles
- Nitrogen adsorption/desorption analysis was performed to determine surface area, pore volume and average pore size of the TiCN/CNT. All three samples had Type IV nitrogen isotherms (ESI†), indicative of the predominantly macroporous nature of the CNT-based foam that serves as the foundation for all the samples. The addition of TiO2 and the conversion to TiCN increased both the surface area and pore volume of the composite foams. Peak pore size increases from 56 nm in the CNT-based foam to 72 nm in the TiO2/CNT and TiCN/CNT. The TiO2/CNT exhibits pore morphology similar to that of an amorphous TiO2 aerogel, suggesting that the TiO2 coating the CNT bundles dominates the nitrogen sorption behavior. The TiCN/CNT maintains the same general morphology as the TiO2/CNT, as evidenced by a similar pore size distribution. However, the surface area and pore volume are increased because of the decreased bulk density and additional porosity due to removal of carbon (in the form of gaseous CO) that occurs during carbothermal reduction. Similar increases in surface area were observed by Berger et al. under similar conditions during the conversion of TiO2 (rutile) and carbon (furnace black or graphite).
- In summary, the synthesis of high surface area TiCN/CNT has been shown by the carbothermal reduction of TiO2 in a CNT-based foam. The resulting monolith was conductive, contained N-rich TiCN nanocrystals decorating CNT bundles and had a surface area of 276 m2/g. The straightforward nature of this method should allow for the synthesis of other high surface area CNT-supported metal nitrides (e.g. ZrN, Si3N4) by simply reducing the respective oxide (e.g. ZrO2, SiO2). Also, by performing the carbothermal reduction in inert gas (e.g. Ar), high surface area carbides (e.g. TiC, SiC) could also be formed. Thus, a new class of monolithic, high surface area CNT-supported carbides and nitrides could be developed with potential for significant contributions in applications such as catalysis.
- This high surface area carbon nanotube-supported titanium carbonitride aerogels example is described in greater detail in the journal article “High surface area carbon nanotube-supported titanium carbonitride aerogels,” by Marcus A. Worsley, Joshua D. Kuntz, Peter J. Pauzauskie, Octavio Cervantes, Joseph M. Zaug, Alex E. Gash, Joe H. Satcher Jr., and Theodore F. Baumann, Journal of Materials Chemestry, 2009, 19, 5503-5506. The in the journal article “High surface area carbon nanotube-supported titanium carbonitride aerogels,” by Marcus A. Worsley, Joshua D. Kuntz, Peter J. Pauzauskie, Octavio Cervantes, Joseph M. Zaug, Alex E. Gash, Joe H. Satcher Jr., and Theodore F. Baumann, Journal of Materials Chemestry, 2009, 19, 5503-5506 is incorporated herein in its entirety by this reference for all purposes.
- Nanocomposites of titania and various forms of carbon (i.e. carbon nanotubes, activated carbons, ordered carbons, etc.) exhibit a number of enhanced functional properties for catalysis and energy-storage applications. Several reports have shown that titania/carbon (TiO2/C) composites have higher photocatalytic activity, improved photoefficiency, and a wider absorption band than titania alone. Composites of TiO2/C have also been shown to improve the energy and power density of electrochemical cells and enhance the storage capacity and reversibility of hydrogen-storage materials. The efficacy of these composite materials depends mainly on the crystallinity and surface area of the titania species. As a result, significant efforts have been focused on the design of high surface area composites containing either rutile or anatase TiO2. One approach to the fabrication of these composites has been the incorporation of the titania within high surface area supports or scaffolds. While this approach has generated a variety of novel titania composites, the surface areas of the composites are typically lower than those of the scaffolds themselves. The decrease in surface area is generally attributed to blocking of the micropores in the support by the deposited titania, decreasing the accessible surface area. The design of a high surface area support containing bimodal porosity (macro- and micropores) could limit the detrimental effects associated with pore-plugging, thereby providing a route to a new class of high surface area titania composites.
- Applicants recently reported the synthesis of activated carbon aerogel (ACA) monoliths that exhibited hierarchical porosity and surface areas in excess of 3000 m2 g−1. In this article, Applicants use these materials as scaffolds for the synthesis of high surface area titania and titanium carbonitride (TiCN) composites. The composites are prepared through coating the inner surfaces of monolithic ACA templates with a layer of sol-gel-derived titania, yielding the TiO2/ACA composite. In a typical synthesis, ACA parts were immersed in the TiO2 sol-gel solution and full infiltration of the ACA pore network by the sol-gel solution was achieved under vacuum. After drying, the amorphous TiO2 overcoat in the composite can then be converted to either anatase TiO2 or titanium carbonitride through heat treatment under different conditions. To convert the amorphous TiO2 layer to anatase, the as-prepared. TiO2/ACA part was heated in air at 400° C. for 2 hours. Alternatively, to prepare the TiCN-coated ACA composite, the as-prepared TiO2/ACA part was heated under flowing nitrogen at 1400° C. for 4 hours. In both cases, the heat-treated composite materials exhibit extremely high BET surface areas (>1800 m2 g−1) and retain the porous network structure of the monolithic ACA support. Because of the technological importance of titania and its well-documented conversion to TiC1-xNx (0<x<1) via carbothermal reduction, these systems were chosen to demonstrate the potential of the ACA as a scaffolding material. Nevertheless, the approach described here is general and can be applied to the fabrication of other high surface area metal oxide, metal nitride and metal carbide composites of interest.
- The microstructures of the titania-ACA composites were evaluated using scanning electron microscopy
FIGS. 6A-D and transmission electron microscopyFIGS. 7A-C . SEM images of as-prepared TiO2/ACAFIGS. 6C-D show the same trabecular structure and texture as observed in the pristine ACAFIGS. 6A-B . The presence of the TiO2 aerogel layer on the surface of the ACA can be seen in images of the as-prepared TiO2/ACA composites. Interestingly, the TiO2 aerogel appears to have formed primarily on the surfaces of the ACA despite the fact that the TiO2 sol-gel solution filled the entire pore volume of the support. As seen inFIGS. 7C-D andFIG. 7A , the open pore volume in the ACA composite is only sparsely populated with TiO2 particles. This observation indicates that nucleation of the TiO2 particles during the sol-gel reaction preferentially occurs at the surface of the ACA. After heat treatment at 400° C., the texture of the TiO2/ACA composite appears to roughen, apparently due to the formation of anatase TiO2 nanocrystals on the ACA surfaceFIG. 6E-F andFIG. 7C . Further changes in texture are seen after carbothermal reduction of the surface layer of TiO2 to TiCNFIG. 6G-H andFIG. 7C . In the TiCN/ACA composite, cubic TiCN crystals ranging in size from 10 to 100 nm are clearly visible on the ACA surface. The continuous nature of the crystalline TiCN layer suggests that the deposited TiO2 completely coated the entire surface of the ACA support. With the bulk of the TiO2 deposited at the ACA surface, the number of TiO2 particles formed in sol filling the free space in the ACA is greatly reduced. - Thermal gravimetric analysis in air was used to determine the TiO2 content in the as-prepared and annealed TiO2/ACA composites as well as the TiCN content in the TiCN/ACA composite. As expected, combustion of the pristine ACA begins oxidizing at 400° C. and the material is completely consumed by 600° C. The onset of mass loss for the annealed TiO2/ACA composite is similar to that of the ACA, but the material retains 20% of its original mass due to the presence of the TiO2 overcoat Table III. In contrast to the ACA and TiO2/ACA materials, the TiCN/ACA composite exhibits a slight weight gain at ˜350° C. prior to combustion of the carbon support. The increase in mass can be attributed to oxidation of the TiCN layer (molecular weight of 60-62) to TiO2 (molecular weight of 80). Interestingly, complete oxidation of the ACA support in the TiCN/ACA composite does not occur until 680° C. as compared to 600° C. for the other samples, suggesting that the TiCN completely covers the ACA surface, providing an effective barrier to oxygen diffusion. In addition, the energy dispersive X-ray spectroscopy (EDX) element mapping of the TiCN/ACA shows an even distribution of Ti, C, and N, consistent with a TiCN layer covering most of the ACA, as observed in the SEM and TEM images. Only after the TiCN is converted to the oxide does combustion of the ACA occur. The remaining 18 wt % TiO2 from combustion of the TiCN/ACA composite implies a starting TiCN content of 14 wt %.
-
TABLE III Physical properties for the ACA support, TiO2 aerogels and the ACA composites Monolithic TiO2/ density/g SRET/ Vtotal/ Vmicro/ Mateiral wt % cm 3 m3 g cm3 g cm3 g ACA 0 0.140 2455 1.05 0.42 TiO2 aerogel 78 0.193 237 0.53 — (as prepared) TiO2 aerogel 99 n.a.a 141 0.33 — (heat-treated) TiO2/ACA 15 0.230 1507 0.91 0.50 (as-prepared) TiO2/ ACA 20 0.104 2054 1.30 0.61 (heat-treated) TiCN/ACA 14b 0.148 1838 1.01 0.43 aThe heat-treated TiO2 aerogel was isolated as a powder, bTiCN content shown for TiCN/ACA. indicates data missing or illegible when filed - Powder XRD was used to determine the crystalline phases of the heat-treated TiO2/ACA and TiCN/ACA composites. For comparison, the XRD pattern of the ACA was also included. The XRD pattern for the as-prepared TiO2/ACA (no heat treatment) was very similar to that of the ACA, likely due to the amorphous nature of the titania, and is, therefore, not shown. The largest peaks in the diffraction pattern for the ACA material can be attributed to the (100) and (101) graphite peaks (PDF #41-1487). These peaks are also visible in the diffraction patterns for the heat-treated TiO2/ACA and TiCN/ACA composites due to the presence of the ACA support. The remaining peaks in the XRD pattern for the annealed TiO2/ACA composite can be indexed to the anatase phase of TiO2 (PDF #21-1272). Analysis of the peaks using the Scherrer equation indicates the average crystallite size is ˜9 nm, in agreement with the small size of the crystals observed by electron microscopy. The XRD peaks for the TiCN/ACA composite indicate the presence of the osbornite crystalline phase of TiCN (PDF #06-0642) on the ACA support. The calculated lattice parameter, a, for the TiCN in the TiCN/ACA, 4.248 Å, is in good agreement with TiC1-xNx (x=0.90) and very close to the value for pure TiN, 4.240. The high nitrogen content is consistent with EDX results showing a Ti:N ratio of close to one. The average crystallites size calculated from the XRD data (˜20 nm) correlates with the size range of the cubic crystals observed in SEM and TEM analysis. Therefore, based on the XRD data, the heat-treated TiO2/ACA composite contained purely anatase nanocrystals, and full reduction of TiO2 to TiCN was achieved in the TiCN/ACA composite to create a highly nitrogen-enriched layer of TiCN nanocrystals on the ACA surface.
- The textural properties of the TiO2/ACA and TiCN/ACA composites were evaluated using nitrogen adsorption/desorption analysis Table III. For comparison, data for the ACA and TiO2 aerogel (before and after heat treatment) are also included in Table III. Nitrogen adsorption/desorption plots for the ACA and the composites. Each of the composites exhibited type II nitrogen isotherms, indicating a mostly macroporous (<2 nm) material with the remaining pore volume primarily in the large meso- and macropore (>90 nm) range. Coating of the ACA framework with TiO2 clearly results in a significant decrease in BET surface area (1507 m2 g−1) relative to the uncoated ACA. Nevertheless, the surface area of the as-prepared TiO2/ACA composite represents almost an order of magnitude improvement over that of the as-prepared TiO2 aerogel. Retention of such a large BET surface area in the coated material suggests that the ACA is less susceptible to the negative effects of pore-plugging observed in other scaffold materials, such as activated carbons. Additionally, heat treatment of the as-prepared TiO2/ACA leads to a 36% increase in surface area in the annealed composite (2054 m2 g−1). This observation is in contrast to the sharp decrease in surface area that occurs upon annealing of the bulk TiO2 aerogel prepared without the scaffold. The increased surface area and pore volume in the annealed composite indicate that the ACA support prevents coarsening and collapse of the TiO2 coating during heat treatment, even as the amorphous titania is converted to the anatase phase. The presence of high-surface area SiO2 has been shown to have similar effects on the temperature stability of pores in TiO2 gels. In addition, correspondingly lower density of the annealed TiO2/ACA (relative to as-prepared TiO2/ACA) is consistent with a lack of pore collapse and likely contributes to the observed textural properties. Similarly, the TiCN/ACA composite also exhibits increased surface area and pore volume relative to the as-prepared TiO2/ACA composite Table III. The increased surface area can be attributed to the additional porosity created by the removal of carbon from the ACA support (in the form of gaseous CO) that occurs during carbothermal reduction. Similar increases in surface area have been reported under similar conditions during the conversion of TiO2 (rutile) and carbon (furnace black or graphite) mixtures to TiCN. While the surface area and pore volume for the TiCN/ACA composite are slightly lower than those of the heat-treated TiO2/ACA, the textural properties are still quite close to those of the original ACA. This observation demonstrates the flexibility of the ACA scaffold for creating a variety of high surface area oxide, carbide and nitride materials.
- In a typical synthesis, titanium(IV) ethoxide (1 g, 0.0125 mol) and ethanol (3.57 g, 0.0776 mol), hydrochloric acid (71.4 μl), and water (851 μl) were mixed in an ice bath, followed by the addition of propylene oxide (0.357 g, 0.00616 mol) to prepare the titania sol. An activated carbon aerogel monolith was immersed in the titania sol in a glass vial and held under vacuum to ensure full penetration of the sol in the carbon aerogel. The reaction mixture was then cured at room temperature for 24 h. The wet composite was washed in ethanol and dried by supercritical extraction in CO2 to yield the TiO2/ACA composite. Annealing the as-prepared TiO2/ACA composite in air at 400° C. for 2 h was required to convert the amorphous titania layer on the ACA to the anatase phase. Alternatively, heating the as-prepared TiO2/ACA composite in flowing nitrogen at 1400° C. for 4 h produced the TiCN/ACA composite.
- Powder X-ray diffraction (XRD) analysis of the samples was performed with Cu Kα radiation on a Scintag PAD-V X-ray diffractometer. TiO2 (anatase) powder was used as a standard. Bulk densities of the monoliths were determined from the physical dimensions and mass of each sample. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) characterization was performed on a JEOL 7401-F at 5-10 keV (20 mA) in SEI mode with a working distance of 2-8 mm. Transmission electron microscopy (TEM) characterization was performed on a JEOL JEM-200CX electron microscope operated at 200 kV. Thermogravimetric analysis (TGA) was performed on a
Shimadzu TGA 50 thermogravimetric analyzer to determine TiO2 and TiCN contents. Samples were heated in flowing air at 10 sccm to 1000° C. at 10° C. min−1 in alumina boats. The weight fraction of material remaining was assumed to be pure stoichiometric TiO2. The TiCN content of the TiCN/ACA was calculated from the weight fraction of TiO2 remaining after heating to 1000° C. in air assuming full oxidation of initial TiCN content. Energy dispersive spectroscopy confirmed that only TiO2 remained after TGA was performed. Surface area determination and pore volume analysis were performed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods using an ASAP 2000 surface area analyzer (Micromeritics Instrument Corporation). Samples of approximately 0.1 g were heated to 300° C. under vacuum (10−5 Torr) for at least 24 h to remove all adsorbed species, prior to analysis. - In conclusion, the synthesis and characterization of TiO2/ACA and TiCN/ACA composites with the highest surfaces areas yet reported has been described. The flexibility of the described method should allow for synthesis of other high surface area metal oxides, carbides, and nitrides through the use of supports with bimodal porosity, like the ACA, to minimize pore-plugging effects. This new class of high-surface area materials should be especially advantageous in technologies such as catalysis and energy storage where high surface area and accessible pore volume are desired.
- This high surface area TiO2/C and TiCN/C composites example is described in greater detail in the journal article “high surface area TiO2/C and TiCN/C composites,” by Marcus A. Worsley, Joshua D. Kuntz, Octavio Cervantes, T. Yong-Jin Han, Alex E. Gash, Joe H. Satcher, Jr and Theodore F. Baumann, Journal of Materials Chemestry, 2009, 19, 7146-7150. The journal article “high surface area TiO2/C and TiCN/C composites,” by Marcus A. Worsley, Joshua D. Kuntz, Octavio Cervantes, T. Yong-Jin Han, Alex E. Gash, Joe H. Satcher, Jr and Theodore F. Baumann, Journal of Materials Chemestry, 2009, 19, 7146-7150 is incorporated herein in its entirety by this reference for all purposes.
- The synthesis and characterization of high surface area carbon-supported silica and silicon carbide aerogels are described. An activated carbon aerogel with surface area greater than 3000 m2/g was used to as a support for the sol-gel deposition of silica. The resulting silica-coated carbon aerogel retained a surface area greater than 2000 m2/g and showed improved thermal stability in air. The carbon-supported silicon carbide aerogel was made by the carbothermal reduction of the silica-coated carbon aerogel under flowing Ar at 1500° C. The resulting monolith maintained a surface area greater than 2000 m2/g and was stable to temperatures approaching 600° C., over 100° C. higher than that of the pristine carbon aerogel.
- The microstructures of the silica-ACA composites were evaluated using scanning electron microscopy
FIGS. 8A and 8B . SEM images of as-prepared SiO2/ACA.FIGS. 8A and 8B show the same trabecular structure and texture as observed in the pristine ACA. The presence of the SiO2 aerogel layer on the surface of the ACA can be seen in images of the as-prepared SiO2/ACA composites. Interestingly, the SiO2 aerogel appears to have formed primarily on the surfaces of the ACA despite the fact that the SiO2 sol-gel solution filled the entire pore volume of the support. As seen inFIGS. 8A and 8B , the open pore volume in the ACA composite is only sparsely populated with SiO2 particles. This observation indicates that nucleation of the SiO2 particles during the sol-gel reaction preferentially occurs at the surface of the ACA. Further changes in texture are seen after carbothermal reduction of the surface layer of SiO2 to SiC (FIGS. 8C and 8D ). In the SiC/ACA composite, virtually no particles are visible in the open pore volume. In fact, the SiC/ACA appears to have the same texture as the pristine ACA suggesting the SIC forms a fairly conformal layer on the ACA. Similar results were observed in the case of TiO2 and TiCN on ACA. - Energy dispersive x-ray analysis was used to track the composition change of the composite during the carbothermal reduction. Oxygen atomic content was used to determine the level of reduction as the SiO2/ACA was populated with SiO2 particles. This observation indicates that nucleation of the SiO2 particles during the sol-gel reaction preferentially occurs at the surface of the ACA. Further changes in texture are seen after carbothermal reduction of the surface layer of SiO2 to SiC (
FIG. 8A-D ). In the SiC/ACA composite, virtually no particles are visible in the open pore volume. In fact, the SiC/ACA appears to have the same texture as the pristine ACA suggesting the SiC forms a fairly conformal layer on the ACA. Similar results were observed in the case of TiO2 and TiCN on ACA. - The carbothermal reduction was considered complete when the O content in the solid phase is reduced to zero. At 1500° C. the O content drops from 12 at % to 3 at % within the first 10 minutes suggesting formation of an SixOyCx phase. The Si and C content show corresponding increases during this initial period. The O content then slowly decreases to zero over the next 5 h. The Si and C content remain fairly constant. Based on these results, it was concluded that a 5 h treatment at 1500° C. was sufficient to completely convert the SiO2 layer in the SiO2/ACA to SIC. This is consistent with literature on SiC synthesis.
- Powder XRD was used to confirm the presence of SiC in the SiC/ACA composite. For comparison, the XRD pattern of the as-prepared SiO2/ACA was also included. The XRD pattern for the pristine ACA is identical to that of the SiO2/ACA, due to the amorphous nature of the as-prepared silica, and is, therefore, not shown. The largest peaks in the diffraction pattern for the SiO2/ACA material can be attributed to the (100) and (101) graphite peaks. These peaks are also visible in the diffraction pattern for the SiC/ACA composites due to the presence of the ACA support. The remaining peaks in the XRD pattern for the SiC/ACA composite can be indexed to moissanite SiC. Analysis of the peaks using the Scherrer equation indicates the average crystallite size is ˜26 nm. Therefore, based on the XRD and EDX data, full reduction of SiO2 to SiC was achieved in the SiC/ACA composite to create a layer of SiC nanocrystals on the ACA surface.
- Thermal gravimetric analysis in air was used to determine the thermal stability of the SiO2/ACA and SiC/ACA, as well as the SiO2 and SiC content. As expected, combustion of the pristine ACA begins at 400° C. and the material is completely consumed by 600° C. The mass loss event below 200° C. for the SiO2/ACA is due to organic impurities from the as-prepared SiO2. The onset of ACA mass loss for the SiO2/ACA composite is ˜100° C. higher than that of the pristine ACA, suggesting that the SiO2 covers the ACA surface fairly well and forms a decent barrier to oxygen diffusion. Similar improvements in thermal stability were noted with a TiCN/ACA. In the case of TiCN/ACA, the TiCN was completely oxidized to TiO2 in the process, in contrast to the SiO2 in the SiO2/ACA. For the SiO2/ACA, complete oxidation of the ACA occurs at 690° C. This material retains 15% of its original mass due to the presence of the SiO2 overcoat. Further improvements in thermal stability are observed in the SiC/ACA composite. Mass loss does not begin until close to 600° C. and complete oxidation of the carbon support does not occur until 720° C. Like the SiO2/ACA, this improved thermal stability suggests that the SiC completely covers the ACA surface, providing an effective barrier to oxygen diffusion. The remaining 10% material remaining represents oxidation-resistant SiC.
- The textural properties of the SiO2/ACA and SiC/ACA composites were evaluated using nitrogen adsorption/desorption analysis (Table 1). Each of the composites exhibited type II nitrogen isotherms, indicating a mostly microporous (<2 nm) material with the remaining pore volume primarily in the large meso- and macropore (>90 nm) range. Coating of the ACA framework with SiO2 clearly results in a significant decrease in BET surface area (2288 m2/g) relative to the uncoated ACA. Nevertheless, the surface area of the as-prepared SiO2/ACA composite represents almost an order of magnitude improvement over that of the as-prepared SiO2 aerogel. Retention of such a large BET surface area in the coated material suggests that the ACA is less susceptible to the negative effects of pore-plugging observed in other scaffold materials, such as activated carbons.
- After carbothermal reduction, the textural properties show little change. There is small loss of surface area and pore volume, likely due to sintering that occurs during the reduction process. While the surface area and pore volume for the SiC/ACA composite are slightly lower than those of the heat-treated SiO2/ACA, the textural properties are still quite close to those of the original ACA. This observation demonstrates the effectiveness of the ACA scaffold for creating high surface area oxide and carbide materials.
- Experimental
- In a typical synthesis, trimethoxysilane (IV) ethoxide (4.1 g) and methanol (14 g), ammonium hydroxide (200 ml), and water (1.5 g) were mixed to prepare the silica sol. An activated carbon aerogel monolith was immersed in the silica sol in a glass vial and held under vacuum to ensure full penetration of the sol in the carbon aerogel. The reaction mixture was then cured at room temperature for 24 h. The wet composite was washed in ethanol and dried by supercritical extraction in CO2 to yield the SiO2/ACA composite. Heating the as-prepared SiO2/ACA composite in flowing argon at 1500° C. for 5 h produced the SiC/ACA composite.
- Powder x-ray diffraction (XRD) analysis of the samples was performed with Cu Ka radiation on a Scintag PAD-V X-ray diffractometer. TiO2 (anatase) powder was used as a standard. Bulk densities of the monoliths were determined from the physical dimensions and mass of each sample. Scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) characterization was performed on a JEOL 7401-F at 5-10 keV (20 mA) in SEI mode with a working distance of 2-8 mm. Transmission electron microscopy (TEM) characterization was performed on a JEOL JEM-200CX Electron Microscope operated at 200 kV. Thermogravimetric analysis (TGA) was performed on a
Shimadzu TGA 50 Thermogravimetric Analyzer to determine SiO2 and SiC content. Samples were heated in flowing air at 10 sccm to 1000° C. at 10° C./min in alumina boats. The weight fraction of material remaining was assumed to be pure stoichiometric SiO2 and SiC. Surface area determination and pore volume analysis were performed by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods using an ASAP 2000 Surface Area Analyzer (Micromeritics Instrument Corporation).42 Samples of approximately 0.1 g were heated to 300° C. under vacuum (10−5 Torr) for at least 24 h to remove all adsorbed species, prior to analysis. - The synthesis and characterization of SiO2/ACA and SiC/ACA composites with the highest surfaces areas yet reported has been described. The flexibility of the described method should allow for synthesis of other high surface area metal oxides, carbides, and nitrides through the use of supports with bimodal porosity, like the ACA, to minimize pore-plugging effects. This new class of high-surface area materials should be especially advantageous in technologies such as catalysis and energy storage where high surface area and accessible pore volume are desired.
- Referring now to
FIG. 9 a flow chart illustrates one embodiment of a method of making a carbon aerogel oxide composite in accordance with the present invention. The method is designated generally by thereference number 900. Themethod 900 includes a number of steps. The steps include dispersing nanotubes in an aqueous media or other media to form a suspension, adding reactants and catalyst to the suspension to create a reaction mixture, curing the reaction mixture to form a wet gel, drying the wet gel to produce a dry gel, pyrolyzing the dry gel to produce a carbon nanotube-based aerogel, immerse the carbon nanotube-based aerogel in a metal oxide sol under a vacuum, returning the carbon nanotube-based aerogel and the metal oxide sol to atmospheric pressure, curing the metal oxide-carbon nanotube-based composite at room temperature, and drying the metal oxide-carbon nanotube-based wet gel composite producing an metal oxide-carbon composite. In one embodiment the step of immersing the carbon nanotube-based aerogel in a metal oxide sol under a vacuum comprises immersing the carbon nanotube-based aerogel in titanium dioxide. In one embodiment the step of immersing the carbon nanotube-based aerogel in a metal oxide sol under a vacuum comprises immersing the carbon nanotube-based aerogel in a metal oxide sol made from Mn, Fe, Co, Ni, Cu, Sn, Al, Si, Zn, Zr sol-gel precursors in combination with catalyst, and sol-gel forming components. Referring again toFIG. 9 , themethod 900 includes a number of steps. The steps shown include the steps described below. -
Step number 901 is “Obtain resorcinol, form-aldehyde, sodium carbonate, sodium dodecylbenzene sulfonate (SDBS) and purified double-walled nanotubes (DWNT).” -
Step number 902 is “Purified DWNTS suspended in aqueous solution containing SDBS.” -
Step number 903 is “Dispersal of DWNTS in aqueous surfactant solution containing SDBS using soniction.” -
Step number 904 is “Resorcinol, formaldehyde and sodium carbonate catalyst added to the reaction solution.” -
Step number 905 is “Sol-Gel mixture transferred to glass molds sealed and cured in oven at 85° C. for 72 hours.” -
Step number 906 is “Resulting gel removed from mold and washed with acetone for 72 hours to remove all water from pores of gel network.” -
Step number 907 is “Wet gel dried with supercritical CO2 and pyrolyzed at 1050° C. under N2 atmosphere for 3 hours.” -
Step number 908 is “Resulting composite material (CA-DWNT) isolated as black cylinder monoliths.” -
Step number 909 is “Immerse in titanium dioxide (Ti 02) sol: infiltration of pore network achieved under vacuum.” -
Step number 910 is “Return to atmospheric pressure and dry wet composite using supercritical CO2 producing a metal oxide-carbon composite. - Referring now to
FIG. 10 a flow chart illustrates an embodiment of a method of making a metal oxide-carbon aerogel composite in accordance with the present invention. The method is designated generally by thereference number 1000. Themethod 1000 includes a number of steps. The steps include providing an aqueous media or other media to form a suspension, adding reactants and catalyst to the suspension to create a reaction mixture, curing the reaction mixture to form a wet gel, drying the wet gel to produce a dry gel, pyrolyzing the dry gel to produce an aerogel, immerse the aerogel in a metal oxide sol under a vacuum, returning the aerogel and the metal oxide sol to atmospheric pressure, curing the metal oxide sol-infiltrated carbon aerogel, and drying the metal oxide-carbon wet gel composite producing a metal oxide-carbon aerogel composite. In one embodiment the step of immersing the carbon aerogel in a metal oxide sol under a vacuum comprises immersing the carbon aerogel in titanium dioxide sol. In one embodiment the step of immersing the carbon aerogel in a metal oxide sol under a vacuum comprises immersing the carbon aerogel in a metal oxide sol made from Mn, Fe, Co, Ni, Cu, Zn, Zr sol-gel precursors in combination with a catalyst, and sol-gel forming components. - Referring again to
FIG. 10 , themethod 1000 includes a number of steps. The steps shown include the steps described below. - Step number 1001 is “Resorcinol and 37% formaldehyde solution dissolved in water.”
-
Step number 1002 is “Add glacial acetic acid.” -
Step number 1003 is “Transferred to glass molds and cured at 80° C. for 72 hours.” -
Step number 1004 is “Resultant organic hydrogels washed with acetone to remove water and dried with supercritical C02.” -
Step number 1005 is “Organic aerogels carbonized at 1050° C. for 3 hours under N2 atmosphere.” -
Step number 1006 is “Carbon monoliths.” - Step number 1007 is “Activating carbon aerogel by exposing to stream of CO2 at 950° for different soak times.”
-
Step number 1008 is “Shorter activation time new porosity is in the form of micropores.” -
Step number 1009 is “Longer activation time. The micropore are widened to sizes that cross the micropore mesopore boundry.” - While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
Claims (14)
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US12/694,425 US20100190639A1 (en) | 2009-01-28 | 2010-01-27 | High surface area, electrically conductive nanocarbon-supported metal oxide |
US13/051,915 US8629076B2 (en) | 2010-01-27 | 2011-03-18 | High surface area silicon carbide-coated carbon aerogel |
US13/281,185 US8664143B2 (en) | 2009-01-27 | 2011-10-25 | High surface area, electrically conductive nanocarbon-supported metal oxide |
US13/281,160 US9087625B2 (en) | 2009-01-27 | 2011-10-25 | Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes |
US14/156,268 US9082524B2 (en) | 2009-01-27 | 2014-01-15 | High surface area, electrically conductive nanocarbon-supported metal oxide |
US14/688,909 US9793026B2 (en) | 2009-01-27 | 2015-04-16 | Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US14780509P | 2009-01-28 | 2009-01-28 | |
US12/694,425 US20100190639A1 (en) | 2009-01-28 | 2010-01-27 | High surface area, electrically conductive nanocarbon-supported metal oxide |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/652,616 Continuation-In-Part US8685287B2 (en) | 2009-01-27 | 2010-01-05 | Mechanically robust, electrically conductive ultralow-density carbon nanotube-based aerogels |
Related Child Applications (5)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/652,616 Continuation US8685287B2 (en) | 2009-01-27 | 2010-01-05 | Mechanically robust, electrically conductive ultralow-density carbon nanotube-based aerogels |
US12/652,616 Continuation-In-Part US8685287B2 (en) | 2009-01-27 | 2010-01-05 | Mechanically robust, electrically conductive ultralow-density carbon nanotube-based aerogels |
US13/051,915 Continuation-In-Part US8629076B2 (en) | 2010-01-27 | 2011-03-18 | High surface area silicon carbide-coated carbon aerogel |
US13/281,185 Continuation US8664143B2 (en) | 2009-01-27 | 2011-10-25 | High surface area, electrically conductive nanocarbon-supported metal oxide |
US13/281,160 Continuation-In-Part US9087625B2 (en) | 2009-01-27 | 2011-10-25 | Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes |
Publications (1)
Publication Number | Publication Date |
---|---|
US20100190639A1 true US20100190639A1 (en) | 2010-07-29 |
Family
ID=42354634
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/694,425 Abandoned US20100190639A1 (en) | 2009-01-27 | 2010-01-27 | High surface area, electrically conductive nanocarbon-supported metal oxide |
US13/281,185 Active 2030-03-29 US8664143B2 (en) | 2009-01-27 | 2011-10-25 | High surface area, electrically conductive nanocarbon-supported metal oxide |
US14/156,268 Active US9082524B2 (en) | 2009-01-27 | 2014-01-15 | High surface area, electrically conductive nanocarbon-supported metal oxide |
Family Applications After (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US13/281,185 Active 2030-03-29 US8664143B2 (en) | 2009-01-27 | 2011-10-25 | High surface area, electrically conductive nanocarbon-supported metal oxide |
US14/156,268 Active US9082524B2 (en) | 2009-01-27 | 2014-01-15 | High surface area, electrically conductive nanocarbon-supported metal oxide |
Country Status (1)
Country | Link |
---|---|
US (3) | US20100190639A1 (en) |
Cited By (37)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100187484A1 (en) * | 2009-01-27 | 2010-07-29 | Worsley Marcus A | Mechanically robust, electrically conductive ultralow-density carbon nanotube-based aerogels |
US20110024698A1 (en) * | 2009-04-24 | 2011-02-03 | Worsley Marcus A | Mechanically Stiff, Electrically Conductive Composites of Polymers and Carbon Nanotubes |
CN102002621A (en) * | 2010-10-09 | 2011-04-06 | 北京航空航天大学 | Carbon-based composite material for sliding block of current collector and preparation method thereof |
US20110236564A1 (en) * | 2010-03-24 | 2011-09-29 | Samhwa Capacitor Co., Ltd. | Preparation method of metal oxide doped monolith carbon aerogel for capacitance capacitor |
US20110253907A1 (en) * | 2010-04-14 | 2011-10-20 | Beijing Funate Innovation Technology Co., Ltd. | Transmission electron microscope micro-grid |
US20120165184A1 (en) * | 2009-06-22 | 2012-06-28 | Nanyang Technological University | Doped catalytic carbonaceous composite materials and uses thereof |
US20120273359A1 (en) * | 2011-04-29 | 2012-11-01 | Suss Matthew E | Flow-through electrode capacitive desalination |
WO2012098345A3 (en) * | 2011-01-17 | 2013-07-11 | Bio Nano Consulting | Cross-linked carbon nanotube networks |
US8629076B2 (en) | 2010-01-27 | 2014-01-14 | Lawrence Livermore National Security, Llc | High surface area silicon carbide-coated carbon aerogel |
JP2014015369A (en) * | 2012-07-11 | 2014-01-30 | Taiyo Nippon Sanso Corp | Production method of oxidation-resistant active carbon |
US8809230B2 (en) | 2010-08-02 | 2014-08-19 | Lawrence Livermore National Security, Llc | Porous substrates filled with nanomaterials |
CN104801328A (en) * | 2015-04-21 | 2015-07-29 | 河北科技大学 | Method for preparing TiO2/g-C3N4 composite photocatalyst at low temperature |
CN104986994A (en) * | 2015-06-15 | 2015-10-21 | 南京工业大学 | Preparation method of blocky zirconium-carbon composite aerogel material |
US20160030908A1 (en) * | 2013-03-06 | 2016-02-04 | Ecole Polytechnique Federale De Lausanne (Epfl) | Titanium oxide aerogel composites |
US9637824B2 (en) | 2013-10-23 | 2017-05-02 | United Technologies Corporation | Coating for metal cellular structure and method therefor |
US10023480B2 (en) * | 2011-03-14 | 2018-07-17 | Ut-Battelle, Llc | Carbon composition with hierarchical porosity, and methods of preparation |
US20180214851A1 (en) * | 2017-01-31 | 2018-08-02 | Auburn University | Material for removing contaminants from water |
US10109845B2 (en) * | 2012-12-21 | 2018-10-23 | Lawrence Livermore National Security, Llc | Methods for making graphene-supported metal oxide monolith |
US10232441B2 (en) | 2014-03-18 | 2019-03-19 | United Technologies Corporation | Fabrication of articles from nanowires |
CN109590012A (en) * | 2018-12-21 | 2019-04-09 | 万华化学集团股份有限公司 | A kind of nitrogen-doped carbon cladding double nano metallic catalyst and its preparation method and application |
US10413894B2 (en) * | 2016-05-20 | 2019-09-17 | The Hong Kong Research Institute Of Textiles And Apparel Limited | Catalysts for degradation of organic pollutants in printing and dyeing wastewater and method of preparation thereof |
US10493432B2 (en) * | 2017-02-16 | 2019-12-03 | Carnegie Mellon University | Photocatalyst / carbon nanotube aerogel composites |
US10563538B2 (en) | 2013-10-23 | 2020-02-18 | United Technologies Corporation | Nanocellular foam damper |
US10614966B2 (en) * | 2014-08-11 | 2020-04-07 | Arizona Board Of Regents On Behalf Of The University Of Arizona | Aligned graphene-carbon nanotube porous carbon composite |
JP2020517666A (en) * | 2017-04-28 | 2020-06-18 | イエフペ エネルジ ヌヴェルIfp Energies Nouvelles | Photocatalytic carbon dioxide reduction method using a photocatalyst in the form of a porous monolith |
US10793450B2 (en) | 2014-12-03 | 2020-10-06 | University Of Kentucky Research Foundation | Potential of zero charge-based capacitive deionization |
US10828400B2 (en) | 2014-06-10 | 2020-11-10 | The Research Foundation For The State University Of New York | Low temperature, nanostructured ceramic coatings |
CN112517069A (en) * | 2020-12-24 | 2021-03-19 | 新乡学院 | Photocatalytic active carbon aerogel material and preparation method thereof |
US20210095899A1 (en) * | 2012-04-26 | 2021-04-01 | Lawrence Livermore National Security, Llc | Adsorption cooling system using metal organic frameworks |
US20210159024A1 (en) * | 2014-10-09 | 2021-05-27 | Fastcap Systems Corporation | Nanostructured electrode for energy storage device |
US20210299633A1 (en) * | 2012-04-26 | 2021-09-30 | Lawrence Livermore National Security, Llc | Adsorption cooling system using metal organic frameworks |
US20210308651A1 (en) * | 2012-04-26 | 2021-10-07 | Lawrence Livermore National Security, Llc | Adsorption cooling system using carbon aerogel |
CN113645820A (en) * | 2021-07-12 | 2021-11-12 | 西安理工大学 | Preparation method of MXene-CNT/carbon aerogel composite material |
US20210402385A1 (en) * | 2020-06-30 | 2021-12-30 | Korea Institute Of Science And Technology | Synthesis of metal oxide catalysts using supercritical carbon dioxide extraction |
US11358883B2 (en) | 2019-02-05 | 2022-06-14 | Lawrence Livermore National Security, Llc | System and method for using ultramicroporous carbon for the selective removal of nitrate with capacitive deionization |
CN115172073A (en) * | 2022-07-08 | 2022-10-11 | 同济大学 | 3D printed oxide/carbon composite aerogel electrode and preparation method thereof |
CN116959774A (en) * | 2022-04-15 | 2023-10-27 | 深圳大学 | MXees-based composite conductive aerogel and preparation method and application thereof |
Families Citing this family (22)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20100190639A1 (en) * | 2009-01-28 | 2010-07-29 | Worsley Marcus A | High surface area, electrically conductive nanocarbon-supported metal oxide |
US20100196237A1 (en) * | 2009-01-30 | 2010-08-05 | General Electric Company | Templated catalyst composition and associated method |
US9314777B2 (en) | 2012-07-27 | 2016-04-19 | Lawrence Livermore National Security, Llc | High surface area graphene-supported metal chalcogenide assembly |
CN103933970A (en) * | 2014-04-17 | 2014-07-23 | 华南理工大学 | Low-temperature SCR smoke denitration catalyst of carbon nano tube load metallic oxide and preparation method thereof |
US9627608B2 (en) * | 2014-09-11 | 2017-04-18 | Lam Research Corporation | Dielectric repair for emerging memory devices |
US9844762B2 (en) | 2014-09-12 | 2017-12-19 | Lawrence Livermore National Security, Llc | Nanoporous metal-carbon composite |
CN104475131B (en) * | 2014-11-20 | 2017-05-10 | 辽宁石油化工大学 | Visible light response type nanosheet bismuth oxychloride catalyst and preparation method thereof |
US10354808B2 (en) | 2015-01-29 | 2019-07-16 | Florida State University Research Foundation, Inc. | Electrochemical energy storage device |
JP6468108B2 (en) * | 2015-07-21 | 2019-02-13 | 東洋インキScホールディングス株式会社 | Resin composition, laminate and method for producing laminate |
CN105719853B (en) * | 2016-03-21 | 2018-01-09 | 青岛大学 | A kind of preparation method of carbon/cobalt acid nickel Aerogel Nanocomposites material |
CN107329927A (en) * | 2016-04-28 | 2017-11-07 | 富泰华工业(深圳)有限公司 | A kind of data-sharing systems and method |
CN107221446B (en) * | 2017-06-08 | 2019-04-12 | 桂林电子科技大学 | A kind of Co-Ni-Mn oxide composite and its preparation method and application |
US20190318882A1 (en) | 2018-04-16 | 2019-10-17 | Florida State University Research Foundation, Inc. | Hybrid lithium-ion battery-capacitor (h-libc) energy storage devices |
CN109585175B (en) * | 2018-11-27 | 2021-03-09 | 合肥工业大学 | Composite aerogel based on SiC nanosheets, and preparation method and energy storage application thereof |
CN109603697B (en) * | 2018-12-24 | 2022-02-15 | 施柏山 | Nano carbon hybrid aerogel and preparation method and application thereof |
CN109759023A (en) * | 2019-01-23 | 2019-05-17 | 南阳师范学院 | A kind of pumpkin base contains TiO2The preparation method of charcoal-aero gel |
CN112002940B (en) * | 2019-05-27 | 2022-02-01 | 新奥科技发展有限公司 | Composite solid electrolyte, preparation method thereof and solid battery |
US11219890B2 (en) * | 2020-04-29 | 2022-01-11 | Chien-Hsing Hsiao | Method for manufacturing catalysis reactant having high efficiency catalysis for thermal reaction |
CN111604015B (en) * | 2020-06-07 | 2022-02-22 | 宁夏大学 | Preparation method of shell-core structure composite material with metal compound coated by nano carbon material |
CN111653437B (en) * | 2020-06-12 | 2022-06-21 | 陕西科技大学 | Layered multi-stage Ti3C2@Ni(OH)2-MnO2Composite electrode material and preparation method thereof |
US20220033263A1 (en) * | 2020-07-31 | 2022-02-03 | Denso Corporation | Carbon nanotube aggregate |
TWI789722B (en) * | 2021-03-16 | 2023-01-11 | 國立中正大學 | Catalyst structure, use thereof and electrochemical device |
Citations (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5260855A (en) * | 1992-01-17 | 1993-11-09 | Kaschmitter James L | Supercapacitors based on carbon foams |
US5409683A (en) * | 1990-08-23 | 1995-04-25 | Regents Of The University Of California | Method for producing metal oxide aerogels |
US5601938A (en) * | 1994-01-21 | 1997-02-11 | Regents Of The University Of California | Carbon aerogel electrodes for direct energy conversion |
US6500401B2 (en) * | 2000-07-20 | 2002-12-31 | Cabot Corporation | Carbon foams and methods of making the same |
US6653356B2 (en) * | 1999-12-13 | 2003-11-25 | Jonathan Sherman | Nanoparticulate titanium dioxide coatings, and processes for the production and use thereof |
US20040176643A1 (en) * | 2000-03-14 | 2004-09-09 | Nippon Soda Co., Ltd. | Novel sulfur compounds and intermolecular compounds containing the same as the component compounds |
US6809060B2 (en) * | 2002-03-13 | 2004-10-26 | Korea Institute Of Science And Technology | Aerogel type platinum-tuthenium-carbon catalyst, method for manufacturing the same and direct methanol fuel cell comprising the same |
US6843919B2 (en) * | 2002-10-04 | 2005-01-18 | Kansas State University Research Foundation | Carbon-coated metal oxide nanoparticles |
US6986818B2 (en) * | 2000-06-02 | 2006-01-17 | The Regents Of The University Of California | Method for producing nanostructured metal-oxides |
US7005401B2 (en) * | 2002-07-09 | 2006-02-28 | Changchun Institute Of Applied Chemistry | Method of preparation of non-platinum composite electrocatalyst for cathode of fuel cell |
US7074880B2 (en) * | 2002-07-22 | 2006-07-11 | Aspen Aerogels, Inc. | Polyimide aerogels, carbon aerogels, and metal carbide aerogels and methods of making same |
US7256147B2 (en) * | 2003-06-20 | 2007-08-14 | Matsushita Electric Industrial Co., Ltd. | Porous body and manufacturing method therefor |
US7270851B2 (en) * | 2004-11-04 | 2007-09-18 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Method for nanoencapsulation of aerogels and nanoencapsulated aerogels produced by such method |
US7282466B2 (en) * | 2004-10-04 | 2007-10-16 | The United States Of America As Represented By The Secretary Of The Navy | Sulfur-functionalized carbon nanoarchitectures as porous, high-surface-area supports for precious metal catalysts |
US20070292732A1 (en) * | 2005-11-30 | 2007-12-20 | Washington, University Of | Carbon-based foam nanocomposite hydrogen storage material |
US7378450B2 (en) * | 2001-12-27 | 2008-05-27 | University Of Connecticut | Aerogel and metallic compositions |
US7410718B2 (en) * | 2003-09-30 | 2008-08-12 | Lawrence Livermore National Security, Llc | Aerogel and xerogel composites for use as carbon anodes |
US20090185327A1 (en) * | 2008-01-17 | 2009-07-23 | Fraser Wade Seymour | Composite electrode comprising a carbon structure coated with a thin film of mixed metal oxides for electrochemical energy storage |
US20090229032A1 (en) * | 2000-12-22 | 2009-09-17 | Aspen Aerogels, Inc. | Method of Manufacturing of Aerogel Composites |
US20090317619A1 (en) * | 2006-12-22 | 2009-12-24 | Roberta Di Monte | Aerogel materials based on metal oxides and composites thereof |
US20100028634A1 (en) * | 2006-07-31 | 2010-02-04 | Turevskaya Evgeniya P | Metal oxide coatings for electrically conductive carbon nanotube films |
US20100139823A1 (en) * | 2008-12-05 | 2010-06-10 | Gash Alexander E | Pyrophoric metal-carbon foam composites and methods of making the same |
US7780875B2 (en) * | 2005-01-13 | 2010-08-24 | Cinvention Ag | Composite materials containing carbon nanoparticles |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6906003B2 (en) | 2003-09-18 | 2005-06-14 | Enernext, Llc | Method for sorption and desorption of molecular gas contained by storage sites of nano-filament laded reticulated aerogel |
US20060293434A1 (en) | 2004-07-07 | 2006-12-28 | The Trustees Of The University Of Pennsylvania | Single wall nanotube composites |
PT1700831E (en) | 2005-03-09 | 2008-01-24 | Gegussa Novara Technology Spa | Process for the production of monoliths by means of the sol-gel process |
CN100386258C (en) | 2006-06-23 | 2008-05-07 | 清华大学 | Aerogel carbon nanotube and its preparation method and application |
US20100190639A1 (en) * | 2009-01-28 | 2010-07-29 | Worsley Marcus A | High surface area, electrically conductive nanocarbon-supported metal oxide |
US8629076B2 (en) * | 2010-01-27 | 2014-01-14 | Lawrence Livermore National Security, Llc | High surface area silicon carbide-coated carbon aerogel |
US9601226B2 (en) * | 2012-12-21 | 2017-03-21 | Lawrence Livermore National Security, Llc | High-density 3D graphene-based monolith and related materials, methods, and devices |
-
2010
- 2010-01-27 US US12/694,425 patent/US20100190639A1/en not_active Abandoned
-
2011
- 2011-10-25 US US13/281,185 patent/US8664143B2/en active Active
-
2014
- 2014-01-15 US US14/156,268 patent/US9082524B2/en active Active
Patent Citations (24)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5409683A (en) * | 1990-08-23 | 1995-04-25 | Regents Of The University Of California | Method for producing metal oxide aerogels |
US5260855A (en) * | 1992-01-17 | 1993-11-09 | Kaschmitter James L | Supercapacitors based on carbon foams |
US5601938A (en) * | 1994-01-21 | 1997-02-11 | Regents Of The University Of California | Carbon aerogel electrodes for direct energy conversion |
US6653356B2 (en) * | 1999-12-13 | 2003-11-25 | Jonathan Sherman | Nanoparticulate titanium dioxide coatings, and processes for the production and use thereof |
US20040176643A1 (en) * | 2000-03-14 | 2004-09-09 | Nippon Soda Co., Ltd. | Novel sulfur compounds and intermolecular compounds containing the same as the component compounds |
US6986818B2 (en) * | 2000-06-02 | 2006-01-17 | The Regents Of The University Of California | Method for producing nanostructured metal-oxides |
US6500401B2 (en) * | 2000-07-20 | 2002-12-31 | Cabot Corporation | Carbon foams and methods of making the same |
US20090229032A1 (en) * | 2000-12-22 | 2009-09-17 | Aspen Aerogels, Inc. | Method of Manufacturing of Aerogel Composites |
US7378450B2 (en) * | 2001-12-27 | 2008-05-27 | University Of Connecticut | Aerogel and metallic compositions |
US6809060B2 (en) * | 2002-03-13 | 2004-10-26 | Korea Institute Of Science And Technology | Aerogel type platinum-tuthenium-carbon catalyst, method for manufacturing the same and direct methanol fuel cell comprising the same |
US7005401B2 (en) * | 2002-07-09 | 2006-02-28 | Changchun Institute Of Applied Chemistry | Method of preparation of non-platinum composite electrocatalyst for cathode of fuel cell |
US7074880B2 (en) * | 2002-07-22 | 2006-07-11 | Aspen Aerogels, Inc. | Polyimide aerogels, carbon aerogels, and metal carbide aerogels and methods of making same |
US6843919B2 (en) * | 2002-10-04 | 2005-01-18 | Kansas State University Research Foundation | Carbon-coated metal oxide nanoparticles |
US7256147B2 (en) * | 2003-06-20 | 2007-08-14 | Matsushita Electric Industrial Co., Ltd. | Porous body and manufacturing method therefor |
US7410718B2 (en) * | 2003-09-30 | 2008-08-12 | Lawrence Livermore National Security, Llc | Aerogel and xerogel composites for use as carbon anodes |
US7282466B2 (en) * | 2004-10-04 | 2007-10-16 | The United States Of America As Represented By The Secretary Of The Navy | Sulfur-functionalized carbon nanoarchitectures as porous, high-surface-area supports for precious metal catalysts |
US7442747B1 (en) * | 2004-10-04 | 2008-10-28 | The United States Of America As Represented By The Secretary Of The Navy | Sulfur-functionalized carbon nanoarchitectures as porous, high surface area supports for precious metal catalysts |
US7270851B2 (en) * | 2004-11-04 | 2007-09-18 | The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration | Method for nanoencapsulation of aerogels and nanoencapsulated aerogels produced by such method |
US7780875B2 (en) * | 2005-01-13 | 2010-08-24 | Cinvention Ag | Composite materials containing carbon nanoparticles |
US20070292732A1 (en) * | 2005-11-30 | 2007-12-20 | Washington, University Of | Carbon-based foam nanocomposite hydrogen storage material |
US20100028634A1 (en) * | 2006-07-31 | 2010-02-04 | Turevskaya Evgeniya P | Metal oxide coatings for electrically conductive carbon nanotube films |
US20090317619A1 (en) * | 2006-12-22 | 2009-12-24 | Roberta Di Monte | Aerogel materials based on metal oxides and composites thereof |
US20090185327A1 (en) * | 2008-01-17 | 2009-07-23 | Fraser Wade Seymour | Composite electrode comprising a carbon structure coated with a thin film of mixed metal oxides for electrochemical energy storage |
US20100139823A1 (en) * | 2008-12-05 | 2010-06-10 | Gash Alexander E | Pyrophoric metal-carbon foam composites and methods of making the same |
Cited By (59)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8685287B2 (en) | 2009-01-27 | 2014-04-01 | Lawrence Livermore National Security, Llc | Mechanically robust, electrically conductive ultralow-density carbon nanotube-based aerogels |
US9460865B2 (en) | 2009-01-27 | 2016-10-04 | Lawrence Livermore National Security, Llc | Mechanically robust, electrically conductive ultralow-density carbon nanotube-based aerogels |
US9384870B2 (en) | 2009-01-27 | 2016-07-05 | Lawrence Livermore National Security, Llc | Mechanically robust, electrically conductive ultralow-density carbon nanotube-based aerogels |
US20100187484A1 (en) * | 2009-01-27 | 2010-07-29 | Worsley Marcus A | Mechanically robust, electrically conductive ultralow-density carbon nanotube-based aerogels |
US20110024698A1 (en) * | 2009-04-24 | 2011-02-03 | Worsley Marcus A | Mechanically Stiff, Electrically Conductive Composites of Polymers and Carbon Nanotubes |
US20120165184A1 (en) * | 2009-06-22 | 2012-06-28 | Nanyang Technological University | Doped catalytic carbonaceous composite materials and uses thereof |
US8629076B2 (en) | 2010-01-27 | 2014-01-14 | Lawrence Livermore National Security, Llc | High surface area silicon carbide-coated carbon aerogel |
US8399046B2 (en) * | 2010-03-24 | 2013-03-19 | Samhwa Capacitor Co., Ltd. | Preparation method of metal oxide doped monolith carbon aerogel for capacitance capacitor |
US20110236564A1 (en) * | 2010-03-24 | 2011-09-29 | Samhwa Capacitor Co., Ltd. | Preparation method of metal oxide doped monolith carbon aerogel for capacitance capacitor |
US20110253907A1 (en) * | 2010-04-14 | 2011-10-20 | Beijing Funate Innovation Technology Co., Ltd. | Transmission electron microscope micro-grid |
US9184023B2 (en) * | 2010-04-14 | 2015-11-10 | Beijing Funate Innovation Technology Co., Ltd. | Transmission electron microscope micro-grid |
USRE46771E1 (en) | 2010-08-02 | 2018-04-03 | Lawrence Livermore National Security, Llc | Porous substrates filled with nanomaterials |
US8809230B2 (en) | 2010-08-02 | 2014-08-19 | Lawrence Livermore National Security, Llc | Porous substrates filled with nanomaterials |
CN102002621A (en) * | 2010-10-09 | 2011-04-06 | 北京航空航天大学 | Carbon-based composite material for sliding block of current collector and preparation method thereof |
US9308479B2 (en) | 2011-01-17 | 2016-04-12 | The Bio Nano Centre Limited | Cross-linked carbon nanotube networks |
WO2012098345A3 (en) * | 2011-01-17 | 2013-07-11 | Bio Nano Consulting | Cross-linked carbon nanotube networks |
CN103459011A (en) * | 2011-01-17 | 2013-12-18 | 生物纳米咨询公司 | Cross-linked carbon nanotube networks |
US9643149B2 (en) | 2011-01-17 | 2017-05-09 | The Bio Nano Centre Limited | Cross-linked carbon nanotube networks |
US10626028B2 (en) | 2011-03-14 | 2020-04-21 | Ut-Battelle, Llc | Carbon composition with hierarchical porosity, and methods of preparation |
US10023480B2 (en) * | 2011-03-14 | 2018-07-17 | Ut-Battelle, Llc | Carbon composition with hierarchical porosity, and methods of preparation |
US20120273359A1 (en) * | 2011-04-29 | 2012-11-01 | Suss Matthew E | Flow-through electrode capacitive desalination |
US11878282B2 (en) * | 2012-04-26 | 2024-01-23 | Lawrence Livermore National Security, Llc | Adsorption cooling system using carbon aerogel |
US20210095899A1 (en) * | 2012-04-26 | 2021-04-01 | Lawrence Livermore National Security, Llc | Adsorption cooling system using metal organic frameworks |
US20210299633A1 (en) * | 2012-04-26 | 2021-09-30 | Lawrence Livermore National Security, Llc | Adsorption cooling system using metal organic frameworks |
US20210346864A1 (en) * | 2012-04-26 | 2021-11-11 | Lawrence Livermore National Security, Llc | Adsorption cooling system using carbon aerogel |
US11786883B2 (en) * | 2012-04-26 | 2023-10-17 | Lawrence Livermore National Security, Llc | Adsorption cooling system using metal organic frameworks |
US20210308651A1 (en) * | 2012-04-26 | 2021-10-07 | Lawrence Livermore National Security, Llc | Adsorption cooling system using carbon aerogel |
US11686508B2 (en) * | 2012-04-26 | 2023-06-27 | Lawrence Livermore National Security, Llc | Adsorption cooling system using metal organic frameworks |
JP2014015369A (en) * | 2012-07-11 | 2014-01-30 | Taiyo Nippon Sanso Corp | Production method of oxidation-resistant active carbon |
US10109845B2 (en) * | 2012-12-21 | 2018-10-23 | Lawrence Livermore National Security, Llc | Methods for making graphene-supported metal oxide monolith |
US10569248B2 (en) * | 2013-03-06 | 2020-02-25 | Ecole polytechnique fédérale de Lausanne (EPFL) | Titanium oxide aerogel composites |
US20160030908A1 (en) * | 2013-03-06 | 2016-02-04 | Ecole Polytechnique Federale De Lausanne (Epfl) | Titanium oxide aerogel composites |
US10563538B2 (en) | 2013-10-23 | 2020-02-18 | United Technologies Corporation | Nanocellular foam damper |
US9637824B2 (en) | 2013-10-23 | 2017-05-02 | United Technologies Corporation | Coating for metal cellular structure and method therefor |
US11162384B2 (en) | 2013-10-23 | 2021-11-02 | Raytheon Technologies Corporation | Nanocellular foam damper |
US10232441B2 (en) | 2014-03-18 | 2019-03-19 | United Technologies Corporation | Fabrication of articles from nanowires |
US10828400B2 (en) | 2014-06-10 | 2020-11-10 | The Research Foundation For The State University Of New York | Low temperature, nanostructured ceramic coatings |
US10614966B2 (en) * | 2014-08-11 | 2020-04-07 | Arizona Board Of Regents On Behalf Of The University Of Arizona | Aligned graphene-carbon nanotube porous carbon composite |
US20230282426A1 (en) * | 2014-10-09 | 2023-09-07 | Fastcap Systems Corporation | Nanostructured electrode for energy storage device |
US11664173B2 (en) * | 2014-10-09 | 2023-05-30 | Fastcap Systems Corporation | Nanostructured electrode for energy storage device |
US20210159024A1 (en) * | 2014-10-09 | 2021-05-27 | Fastcap Systems Corporation | Nanostructured electrode for energy storage device |
US11942271B2 (en) * | 2014-10-09 | 2024-03-26 | Fastcap Systems Corporation | Nanostructured electrode for energy storage device |
US10793450B2 (en) | 2014-12-03 | 2020-10-06 | University Of Kentucky Research Foundation | Potential of zero charge-based capacitive deionization |
CN104801328A (en) * | 2015-04-21 | 2015-07-29 | 河北科技大学 | Method for preparing TiO2/g-C3N4 composite photocatalyst at low temperature |
CN104986994A (en) * | 2015-06-15 | 2015-10-21 | 南京工业大学 | Preparation method of blocky zirconium-carbon composite aerogel material |
US10413894B2 (en) * | 2016-05-20 | 2019-09-17 | The Hong Kong Research Institute Of Textiles And Apparel Limited | Catalysts for degradation of organic pollutants in printing and dyeing wastewater and method of preparation thereof |
US10987653B2 (en) * | 2017-01-31 | 2021-04-27 | Auburn University | Material for removing contaminants from water |
US20180214851A1 (en) * | 2017-01-31 | 2018-08-02 | Auburn University | Material for removing contaminants from water |
US10493432B2 (en) * | 2017-02-16 | 2019-12-03 | Carnegie Mellon University | Photocatalyst / carbon nanotube aerogel composites |
JP7085567B2 (en) | 2017-04-28 | 2022-06-16 | イエフペ エネルジ ヌヴェル | Photocatalytic carbon dioxide reduction method using a photocatalyst in the form of a porous monolith |
JP2020517666A (en) * | 2017-04-28 | 2020-06-18 | イエフペ エネルジ ヌヴェルIfp Energies Nouvelles | Photocatalytic carbon dioxide reduction method using a photocatalyst in the form of a porous monolith |
CN109590012A (en) * | 2018-12-21 | 2019-04-09 | 万华化学集团股份有限公司 | A kind of nitrogen-doped carbon cladding double nano metallic catalyst and its preparation method and application |
US11358883B2 (en) | 2019-02-05 | 2022-06-14 | Lawrence Livermore National Security, Llc | System and method for using ultramicroporous carbon for the selective removal of nitrate with capacitive deionization |
US11724252B2 (en) * | 2020-06-30 | 2023-08-15 | Korea Institute Of Science And Technology | Synthesis of metal oxide catalysts using supercritical carbon dioxide extraction |
US20210402385A1 (en) * | 2020-06-30 | 2021-12-30 | Korea Institute Of Science And Technology | Synthesis of metal oxide catalysts using supercritical carbon dioxide extraction |
CN112517069A (en) * | 2020-12-24 | 2021-03-19 | 新乡学院 | Photocatalytic active carbon aerogel material and preparation method thereof |
CN113645820A (en) * | 2021-07-12 | 2021-11-12 | 西安理工大学 | Preparation method of MXene-CNT/carbon aerogel composite material |
CN116959774A (en) * | 2022-04-15 | 2023-10-27 | 深圳大学 | MXees-based composite conductive aerogel and preparation method and application thereof |
CN115172073A (en) * | 2022-07-08 | 2022-10-11 | 同济大学 | 3D printed oxide/carbon composite aerogel electrode and preparation method thereof |
Also Published As
Publication number | Publication date |
---|---|
US9082524B2 (en) | 2015-07-14 |
US20120122652A1 (en) | 2012-05-17 |
US20140217330A1 (en) | 2014-08-07 |
US8664143B2 (en) | 2014-03-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US9082524B2 (en) | High surface area, electrically conductive nanocarbon-supported metal oxide | |
US8629076B2 (en) | High surface area silicon carbide-coated carbon aerogel | |
US8809230B2 (en) | Porous substrates filled with nanomaterials | |
Tang et al. | 3D hierarchical porous graphene-based energy materials: synthesis, functionalization, and application in energy storage and conversion | |
Kim et al. | Rational design and synthesis of extremely efficient macroporous CoSe2–CNT composite microspheres for hydrogen evolution reaction | |
US10106418B2 (en) | Graphene aerogels | |
Oztuna et al. | Graphene aerogel supported Pt electrocatalysts for oxygen reduction reaction by supercritical deposition | |
Thompson et al. | Iron-catalyzed graphitization of biomass | |
Yu et al. | Supercapacitor electrode materials: nanostructures from 0 to 3 dimensions | |
Fan et al. | Carbon nanosheets: synthesis and application | |
Lee et al. | Cobalt-based compounds and composites as electrode materials for high-performance electrochemical capacitors | |
Zhang et al. | Fe–N doped carbon nanotube/graphene composite: facile synthesis and superior electrocatalytic activity | |
Liang et al. | TiO 2 nanocrystals grown on graphene as advanced photocatalytic hybrid materials | |
JP4004502B2 (en) | Method for producing ultrafine fibrous nanocarbon | |
Li et al. | Nitrogen‐Doped Graphitic Porous Carbon Nanosheets Derived from In Situ Formed g‐C3N4 Templates for the Oxygen Reduction Reaction | |
Worsley et al. | Carbon aerogels | |
KR20160092987A (en) | Bulk preparation of holey carbon allotropes via controlled catalytic oxidation | |
Kim et al. | Synthesis of hierarchical linearly assembled graphitic carbon nanoparticles via catalytic graphitization in SBA-15 | |
Zhang et al. | Homogeneous sulphur-doped composites: porous carbon materials with unique hierarchical porous nanostructure for super-capacitor application | |
JP2008280203A (en) | Nitrogen-doped mesoporous carbon (n-kit-6) and its production method | |
Worsley et al. | Synthesis and characterization of monolithic, high surface area SiO 2/C and SiC/C composites | |
Ragavan et al. | Facile synthesis and supercapacitor performances of nitrogen doped CNTs grown over mesoporous Fe/SBA-15 catalyst | |
You et al. | Development of stable electrochemical catalysts using ordered mesoporous carbon/silicon carbide nanocomposites | |
Worsley et al. | High surface area carbon nanotube-supported titanium carbonitride aerogels | |
Samuels et al. | Three dimensional hybrid multi-layered graphene–CNT catalyst supports via rapid thermal annealing of nickel acetate |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: LAWRENCE LIVERMORE NATIONAL SECURITY, LLC, CALIFOR Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:WORSLEY, MARCUS A.;HAN, THOMAS YON-JIN;KUNTZ, JOSHUA D.;AND OTHERS;SIGNING DATES FROM 20100120 TO 20100125;REEL/FRAME:023954/0415 |
|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO PAY ISSUE FEE |
|
AS | Assignment |
Owner name: U.S. DEPARTMENT OF ENERGY, DISTRICT OF COLUMBIA Free format text: CONFIRMATORY LICENSE;ASSIGNOR:LAWRENCE LIVERMORE NATIONAL SECURITY, LLC;REEL/FRAME:027607/0935 Effective date: 20111222 |