JP2014031281A - Titanium oxide production method, titanium oxide, photocatalyst, and photoelectrode of dye-sensitized solar cell - Google Patents
Titanium oxide production method, titanium oxide, photocatalyst, and photoelectrode of dye-sensitized solar cell Download PDFInfo
- Publication number
- JP2014031281A JP2014031281A JP2012170721A JP2012170721A JP2014031281A JP 2014031281 A JP2014031281 A JP 2014031281A JP 2012170721 A JP2012170721 A JP 2012170721A JP 2012170721 A JP2012170721 A JP 2012170721A JP 2014031281 A JP2014031281 A JP 2014031281A
- Authority
- JP
- Japan
- Prior art keywords
- titanium oxide
- titanium
- precursor
- heat treatment
- diol
- 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.)
- Pending
Links
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 title claims abstract description 203
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 title claims abstract description 198
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 40
- 239000011941 photocatalyst Substances 0.000 title claims description 20
- 238000000034 method Methods 0.000 claims abstract description 79
- 239000002243 precursor Substances 0.000 claims abstract description 55
- 238000010438 heat treatment Methods 0.000 claims abstract description 41
- 239000010936 titanium Substances 0.000 claims abstract description 40
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 40
- 150000002009 diols Chemical class 0.000 claims abstract description 25
- 230000001699 photocatalysis Effects 0.000 claims abstract description 20
- 230000008016 vaporization Effects 0.000 claims abstract description 20
- -1 titanium alkoxide Chemical class 0.000 claims abstract description 18
- 238000009834 vaporization Methods 0.000 claims abstract description 12
- 230000000694 effects Effects 0.000 claims abstract description 8
- IKHGUXGNUITLKF-UHFFFAOYSA-N Acetaldehyde Chemical compound CC=O IKHGUXGNUITLKF-UHFFFAOYSA-N 0.000 claims description 24
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 22
- 239000011148 porous material Substances 0.000 claims description 16
- 238000001035 drying Methods 0.000 claims description 15
- 238000001704 evaporation Methods 0.000 claims description 14
- 239000000463 material Substances 0.000 claims description 12
- 239000002245 particle Substances 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 10
- 150000004703 alkoxides Chemical class 0.000 claims description 10
- 238000010304 firing Methods 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 claims description 10
- 239000002184 metal Substances 0.000 claims description 10
- 238000009826 distribution Methods 0.000 claims description 9
- 230000015572 biosynthetic process Effects 0.000 claims description 6
- 238000000354 decomposition reaction Methods 0.000 claims description 6
- 239000011164 primary particle Substances 0.000 claims description 6
- 230000004043 responsiveness Effects 0.000 claims description 2
- 238000005229 chemical vapour deposition Methods 0.000 abstract description 23
- 239000012808 vapor phase Substances 0.000 abstract description 2
- 238000006243 chemical reaction Methods 0.000 description 14
- 239000007789 gas Substances 0.000 description 14
- 239000012071 phase Substances 0.000 description 9
- 238000002360 preparation method Methods 0.000 description 9
- 239000002994 raw material Substances 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 238000010521 absorption reaction Methods 0.000 description 7
- 230000008020 evaporation Effects 0.000 description 7
- 238000001878 scanning electron micrograph Methods 0.000 description 6
- JMXKSZRRTHPKDL-UHFFFAOYSA-N titanium ethoxide Chemical compound [Ti+4].CC[O-].CC[O-].CC[O-].CC[O-] JMXKSZRRTHPKDL-UHFFFAOYSA-N 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 5
- PUPZLCDOIYMWBV-UHFFFAOYSA-N (+/-)-1,3-Butanediol Chemical compound CC(O)CCO PUPZLCDOIYMWBV-UHFFFAOYSA-N 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 239000007791 liquid phase Substances 0.000 description 4
- 238000012545 processing Methods 0.000 description 4
- 238000012827 research and development Methods 0.000 description 4
- 239000012798 spherical particle Substances 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 238000001308 synthesis method Methods 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000005979 thermal decomposition reaction Methods 0.000 description 3
- SVTBMSDMJJWYQN-UHFFFAOYSA-N 2-methylpentane-2,4-diol Chemical compound CC(O)CC(C)(C)O SVTBMSDMJJWYQN-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 230000005587 bubbling Effects 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 229910001873 dinitrogen Inorganic materials 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- 238000001228 spectrum Methods 0.000 description 2
- VXUYXOFXAQZZMF-UHFFFAOYSA-N titanium(IV) isopropoxide Chemical compound CC(C)O[Ti](OC(C)C)(OC(C)C)OC(C)C VXUYXOFXAQZZMF-UHFFFAOYSA-N 0.000 description 2
- DNIAPMSPPWPWGF-VKHMYHEASA-N (+)-propylene glycol Chemical compound C[C@H](O)CO DNIAPMSPPWPWGF-VKHMYHEASA-N 0.000 description 1
- DNIAPMSPPWPWGF-GSVOUGTGSA-N (R)-(-)-Propylene glycol Chemical compound C[C@@H](O)CO DNIAPMSPPWPWGF-GSVOUGTGSA-N 0.000 description 1
- YPFDHNVEDLHUCE-UHFFFAOYSA-N 1,3-propanediol Substances OCCCO YPFDHNVEDLHUCE-UHFFFAOYSA-N 0.000 description 1
- QUVMSYUGOKEMPX-UHFFFAOYSA-N 2-methylpropan-1-olate;titanium(4+) Chemical compound [Ti+4].CC(C)C[O-].CC(C)C[O-].CC(C)C[O-].CC(C)C[O-] QUVMSYUGOKEMPX-UHFFFAOYSA-N 0.000 description 1
- SDTMFDGELKWGFT-UHFFFAOYSA-N 2-methylpropan-2-olate Chemical compound CC(C)(C)[O-] SDTMFDGELKWGFT-UHFFFAOYSA-N 0.000 description 1
- LLQPHQFNMLZJMP-UHFFFAOYSA-N Fentrazamide Chemical compound N1=NN(C=2C(=CC=CC=2)Cl)C(=O)N1C(=O)N(CC)C1CCCCC1 LLQPHQFNMLZJMP-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- LCKIEQZJEYYRIY-UHFFFAOYSA-N Titanium ion Chemical compound [Ti+4] LCKIEQZJEYYRIY-UHFFFAOYSA-N 0.000 description 1
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 238000004887 air purification Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 230000000844 anti-bacterial effect Effects 0.000 description 1
- 230000003373 anti-fouling effect Effects 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000000889 atomisation Methods 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- YHWCPXVTRSHPNY-UHFFFAOYSA-N butan-1-olate;titanium(4+) Chemical compound [Ti+4].CCCC[O-].CCCC[O-].CCCC[O-].CCCC[O-] YHWCPXVTRSHPNY-UHFFFAOYSA-N 0.000 description 1
- BMRWNKZVCUKKSR-UHFFFAOYSA-N butane-1,2-diol Chemical compound CCC(O)CO BMRWNKZVCUKKSR-UHFFFAOYSA-N 0.000 description 1
- OWBTYPJTUOEWEK-UHFFFAOYSA-N butane-2,3-diol Chemical compound CC(O)C(C)O OWBTYPJTUOEWEK-UHFFFAOYSA-N 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000011362 coarse particle Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000001877 deodorizing effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 238000007602 hot air drying Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 231100000053 low toxicity Toxicity 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- DNIAPMSPPWPWGF-UHFFFAOYSA-N monopropylene glycol Natural products CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 1
- 150000002902 organometallic compounds Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- WCVRQHFDJLLWFE-UHFFFAOYSA-N pentane-1,2-diol Chemical compound CCCC(O)CO WCVRQHFDJLLWFE-UHFFFAOYSA-N 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 238000000053 physical method Methods 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920000166 polytrimethylene carbonate Polymers 0.000 description 1
- 235000013772 propylene glycol Nutrition 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000003980 solgel method Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000004729 solvothermal method Methods 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 230000036962 time dependent Effects 0.000 description 1
- 229910052718 tin Inorganic materials 0.000 description 1
- 239000011135 tin Substances 0.000 description 1
- 238000007601 warm air drying Methods 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Classifications
-
- 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
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/542—Dye sensitized solar cells
-
- 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
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Landscapes
- Photovoltaic Devices (AREA)
- Hybrid Cells (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Catalysts (AREA)
Abstract
Description
本発明は酸化チタン製造方法、酸化チタン、光触媒、および色素増感太陽電池の光電極に係り、特に従来に増して光触媒機能を高活性化することのできる、酸化チタン製造方法および酸化チタン等に関する。 The present invention relates to a titanium oxide production method, titanium oxide, a photocatalyst, and a photoelectrode of a dye-sensitized solar cell, and more particularly to a titanium oxide production method, titanium oxide, and the like that can activate the photocatalytic function more than ever. .
酸化チタンは化学的に安定で毒性が少ないことから、従前から顔料や触媒担体として利用されている他、光吸収によって生じる酸化力が防汚、脱臭、空気浄化、水質浄化、抗菌などに対して有効であることが報告されて以来、幅広い分野で応用が拡大している。 Titanium oxide is chemically stable and has low toxicity, so it has been used as a pigment and catalyst carrier, and the oxidizing power caused by light absorption is antifouling, deodorizing, air purification, water purification, antibacterial, etc. Since it was reported to be effective, its application has expanded in a wide range of fields.
酸化チタンはその結晶系、粒子径、比表面積によって光触媒活性が大きく変化することが知られている。そのため、酸化チタンの合成方法によって光触媒活性は大幅に変化する。酸化チタンの合成は多くの場合、液相中で反応させることが多い。溶液中で生成した酸化チタンは粒子が粗大であり、比表面積も大きなものは得られにくい。そこで、液相反応法でも、アルコキシドの加水分解を利用したゾルーゲル法やソルボサーマル法など、多種多様な合成方法が従来提案されている。一方、スパッタ法に代表されるように、物理的な手法で基材表面に酸化チタンを付着させる方法などもよく知られている。 It is known that the photocatalytic activity of titanium oxide varies greatly depending on its crystal system, particle diameter, and specific surface area. Therefore, the photocatalytic activity varies greatly depending on the titanium oxide synthesis method. In many cases, titanium oxide is often reacted in a liquid phase. Titanium oxide produced in a solution has coarse particles and a large specific surface area is difficult to obtain. Therefore, various types of synthesis methods such as a sol-gel method utilizing alkoxide hydrolysis and a solvothermal method have also been proposed in the liquid phase reaction method. On the other hand, as represented by sputtering, a method of attaching titanium oxide to a substrate surface by a physical method is well known.
なお、酸化チタン光触媒については従来、多くの技術的提案がなされている。本願発明者らもこれまで複数の発明を開示しているが、特に後掲特許文献１においては、チタンアルコキシドとジオールから生成する角柱状の酸化チタンが高い光触媒活性を示すことを明らかにしており、これは既に特許されている。この角柱状酸化チタンでは、液相中で酸化チタン前駆体が生成し、これを熱分解することによって高い光触媒活性を示すことも明らかとなっている。 Many technical proposals have been made for titanium oxide photocatalysts. The inventors of the present application have disclosed a plurality of inventions, and in particular, Patent Document 1 listed below has revealed that prismatic titanium oxide formed from titanium alkoxide and diol exhibits high photocatalytic activity. This has already been patented. In this prismatic titanium oxide, it is also clear that a titanium oxide precursor is generated in the liquid phase and exhibits high photocatalytic activity by thermal decomposition.
さて上述のとおり、溶液中でチタンアルコキシドとジオールを反応させて生成する角柱状酸化チタンにおいては、酸化チタン前駆体の生成とその熱分解が、高活性な光触媒活性に寄与していることが明らかになっている。一方、気相中で反応させるＣＶＤ法は、酸化チタン前駆体粒子の成長を防ぐことができるため、酸化チタンの微粒子化に適しているといえる。 As described above, in the prismatic titanium oxide produced by reacting titanium alkoxide and diol in solution, it is clear that the production of titanium oxide precursor and its thermal decomposition contribute to highly active photocatalytic activity. It has become. On the other hand, the CVD method in which the reaction is performed in a gas phase can prevent the growth of titanium oxide precursor particles, and thus can be said to be suitable for making titanium oxide fine particles.
本発明の課題は、これら従来技術の状況を踏まえ、微粒子化に適しているＣＶＤ法によってより高活性な光触媒機能を有する酸化チタンを得ることのできる酸化チタン製造方法を提供し、およびそれによる酸化チタンならびに光触媒を提供することである。 An object of the present invention is to provide a titanium oxide production method capable of obtaining titanium oxide having a more active photocatalytic function by a CVD method suitable for atomization based on the state of these prior arts, and oxidation by the same It is to provide titanium as well as a photocatalyst.
本願発明者は上記課題について検討した結果、チタンアルコキシドとジオールを原料にしたＣＶＤ法によって酸化チタン前駆体の連続合成を行う方法を基礎として上記課題を解決できることに想到し、本発明に至った。すなわち、上記課題を解決するための手段として本願で特許請求される発明、もしくは少なくとも開示される発明は、以下の通りである。 As a result of studying the above problems, the present inventor has conceived that the above problems can be solved on the basis of a method of continuously synthesizing a titanium oxide precursor by a CVD method using titanium alkoxide and diol as raw materials, and has reached the present invention. That is, the invention claimed in the present application, or at least the disclosed invention, as means for solving the above-described problems is as follows.
（１） ジオールおよびチタンアルコキシドを気化させる気化過程と、気化したジオールおよびチタンアルコキシドを気相中で反応させて酸化チタン前駆体を生成する前駆体生成過程と、生成した酸化チタン前駆体を熱処理してアナターゼ型酸化チタンを得る熱処理過程とを備えてなる、酸化チタン製造方法。
（２） 前記酸化チタン前駆体は球状であることを特徴とする、（１）に記載の酸化チタン製造方法。
（３） 前記熱処理過程では１５０℃以下の低温加熱でアナターゼ型酸化チタンが生成可能であることを特徴とする、（１）または（２）に記載の酸化チタン製造方法。
（４） 前記熱処理過程は、水中捕集された前記酸化チタン前駆体を蒸発乾固する蒸発乾固過程と、蒸発乾固した該酸化チタン前駆体を焼成する焼成過程とからなることを特徴とする、（１）ないし（３）のいずれかに記載の酸化チタン製造方法。
(1) A vaporization process for vaporizing diol and titanium alkoxide, a precursor production process for reacting vaporized diol and titanium alkoxide in a gas phase to produce a titanium oxide precursor, and heat treatment of the produced titanium oxide precursor. And a heat treatment process for obtaining anatase-type titanium oxide.
(2) The method for producing titanium oxide according to (1), wherein the titanium oxide precursor is spherical.
(3) The method for producing titanium oxide according to (1) or (2), wherein in the heat treatment process, anatase-type titanium oxide can be produced by low-temperature heating at 150 ° C. or lower.
(4) The heat treatment process includes an evaporation to dryness process for evaporating and drying the titanium oxide precursor collected in water, and a firing process for firing the evaporated and dried titanium oxide precursor. The method for producing titanium oxide according to any one of (1) to (3).
（５） （１）ないし（４）のいずれかに記載の酸化チタン製造方法により製造された、酸化チタン。
（６） 球状の形態であることを特徴とする、（５）に記載の酸化チタン。
（７） 前記球状の形態は粒径２０ｎｍ以下の一次粒子によって構成されていることを特徴とする、（６）に記載の酸化チタン。
（８） 比表面積がＤｅｇｕｓｓａ（登録商標）社製Ｐ２５酸化チタンの３倍以上であることを特徴とする、（５）ないし（７）のいずれかに記載の酸化チタン。
（９） 平均細孔径が１０ｎｍ以下であり、細孔径分布がＤｅｇｕｓｓａ（登録商標）社製Ｐ２５酸化チタンよりも均一であることを特徴とする、（５）ないし（８）のいずれかに記載の酸化チタン。
(5) Titanium oxide manufactured by the titanium oxide manufacturing method according to any one of (1) to (4).
(6) The titanium oxide according to (5), which has a spherical form.
(7) The titanium oxide according to (6), wherein the spherical form is constituted by primary particles having a particle size of 20 nm or less.
(8) The titanium oxide according to any one of (5) to (7), wherein the specific surface area is three times or more of P25 titanium oxide manufactured by Degussa (registered trademark).
(9) The average pore size is 10 nm or less, and the pore size distribution is more uniform than P25 titanium oxide manufactured by Degussa (registered trademark), according to any one of (5) to (8) Titanium oxide.
（１０） アセトアルデヒド分解活性がＤｅｇｕｓｓａ（登録商標）社製Ｐ２５酸化チタンよりも高いことを特徴とする、（５）ないし（９）のいずれかに記載の酸化チタン。
（１１） 可視領域に吸収を示す可視光応答性であることを特徴とする、（５）ないし（１０）のいずれかに記載の酸化チタン。
（１２） 起電力がＰｅｃｃｅｌｌ（登録商標）社製チタンペーストよりも高いことを特徴とする、（５）ないし（１１）のいずれかに記載の酸化チタン。
（１３） 光触媒材料として用いられることを特徴とする、（５）ないし（１２）のいずれかに記載の酸化チタン。
(10) The titanium oxide according to any one of (5) to (9), wherein the acetaldehyde decomposing activity is higher than that of P25 titanium oxide manufactured by Degussa (registered trademark).
(11) The titanium oxide according to any one of (5) to (10), wherein the titanium oxide has visible light responsiveness showing absorption in a visible region.
(12) The titanium oxide according to any one of (5) to (11), wherein the electromotive force is higher than that of a titanium paste manufactured by Peccell (registered trademark).
(13) The titanium oxide according to any one of (5) to (12), which is used as a photocatalytic material.
（１４） 色素増感太陽電池の光電極材料として用いられることを特徴とする、（５）ないし（１２）のいずれかに記載の酸化チタン。
（１５） （５）ないし（１２）のいずれかに記載の酸化チタンを用いた、光触媒。
（１６） （５）ないし（１２）のいずれかに記載の酸化チタンを用いた、色素増感太陽電池の光電極。
（１７） ジオールおよび金属アルコキシドを気化させる気化過程と、気化したジオールおよび金属アルコキシドを気相中で反応させて酸化物前駆体を生成する前駆体生成過程と、生成した酸化物前駆体を熱処理して酸化物を得る熱処理過程とを備えてなる、酸化物製造方法。
(14) The titanium oxide according to any one of (5) to (12), which is used as a photoelectrode material for a dye-sensitized solar cell.
(15) A photocatalyst using the titanium oxide according to any one of (5) to (12).
(16) A photoelectrode for a dye-sensitized solar cell using the titanium oxide according to any one of (5) to (12).
(17) A vaporization process for vaporizing a diol and a metal alkoxide, a precursor generation process for generating an oxide precursor by reacting the vaporized diol and metal alkoxide in a gas phase, and heat-treating the generated oxide precursor. And a heat treatment process for obtaining an oxide.
本発明の酸化チタン製造方法、酸化チタン、光触媒、および色素増感太陽電池の光電極は上述のように構成されるため、これらによれば、より微粒子化できるとともにより高活性な光触媒機能を有する酸化チタンを得ることができる。簡便かつ安価な方法によって連続的に高活性な酸化チタン粉末の合成が可能となる。また本発明により得られる酸化チタンは、色素増感太陽電池光電極に応用した場合、高い起電力を発生することができる。 Since the photoelectrode of the titanium oxide production method, titanium oxide, photocatalyst, and dye-sensitized solar cell of the present invention is configured as described above, according to these, it can be made finer and has a more active photocatalytic function. Titanium oxide can be obtained. A highly active titanium oxide powder can be continuously synthesized by a simple and inexpensive method. Moreover, the titanium oxide obtained by this invention can generate | occur | produce a high electromotive force, when it applies to a dye-sensitized solar cell photoelectrode.
以下、本発明について図面を用いつつ、より詳細に説明する。
図Ｐ１は、本発明の酸化チタン製造方法の基本構成を示すフロー図である。図示するように本製造方法は、ジオール１およびチタンアルコキシド２を気化させる気化過程Ｐ１と、気化したジオール１３およびチタンアルコキシド２４を気相中で反応させて酸化チタン前駆体３５を生成する前駆体生成過程Ｐ２と、生成した酸化チタン前駆体３５を熱処理してアナターゼ型酸化チタン５０を得る熱処理過程Ｐ３とを備えることを、主たる構成とする。
Hereinafter, the present invention will be described in more detail with reference to the drawings.
FIG. P1 is a flowchart showing the basic structure of the titanium oxide production method of the present invention. As shown in the figure, in this production method, a precursor generation for generating a titanium oxide precursor 35 by reacting the vaporized diol 13 and titanium alkoxide 24 in the gas phase with the vaporization process P1 for vaporizing the diol 1 and titanium alkoxide 2. The main configuration includes the process P2 and the heat treatment process P3 in which the produced titanium oxide precursor 35 is heat-treated to obtain the anatase-type titanium oxide 50.
かかる構成により本フローによれば、気化過程Ｐ１においてジオール１およびチタンアルコキシド２が気化し、次いで前駆体生成過程Ｐ２において、気化過程Ｐ１で気化したジオール１３およびチタンアルコキシド２４が気相中にて反応し酸化チタン前駆体３５が生成し、次いで熱処理過程Ｐ３において、酸化チタン前駆体３５が熱処理されることによって、最終的にアナターゼ型酸化チタン５０が製造される。 With this configuration, according to this flow, diol 1 and titanium alkoxide 2 are vaporized in vaporization process P1, and then diol 13 and titanium alkoxide 24 vaporized in vaporization process P1 react in the vapor phase in precursor generation process P2. Then, the titanium oxide precursor 35 is generated, and then the titanium oxide precursor 35 is heat-treated in the heat treatment process P3, whereby the anatase-type titanium oxide 50 is finally produced.
すなわち本発明の酸化チタン製造方法は、気相中におけるジオール１と金属アルコキシド（チタンアルコキシド２）の反応によって、極めて微細な酸化チタン前駆体（チタンジオレート）３５を生成させ、これを熱分解することによって粒子成長を抑制し、高い比表面積を有するアナターゼ型酸化チタン５０を得るものである。得られるアナターゼ型酸化チタン５０は従来よりも高活性の光触媒機能を有するものとなるため、本発明によって、従来にも増して高活性な酸化チタン光触媒を得ることができる。 That is, the titanium oxide production method of the present invention generates a very fine titanium oxide precursor (titanium diolate) 35 by the reaction of diol 1 and metal alkoxide (titanium alkoxide 2) in the gas phase, and thermally decomposes this. Thus, the particle growth is suppressed, and the anatase-type titanium oxide 50 having a high specific surface area is obtained. Since the obtained anatase-type titanium oxide 50 has a photocatalytic function having a higher activity than before, the present invention makes it possible to obtain a titanium oxide photocatalyst having a higher activity than before.
なお、チタンアルコキシドとしては、オルトチタン酸テトラエチル、チタン（ＩＶ）ｎ−ブトキシド、チタン（ＩＶ）ｔ−ブトキシド、チタン（ＩＶ）エトキシド、チタン（ＩＶ）ｉ−プロポキシド、チタン（ＩＶ）イソブトキシド、チタン（ＩＶ）イソプロポキシド 等を好適に使用することができる。 As titanium alkoxide, tetraethyl orthotitanate, titanium (IV) n-butoxide, titanium (IV) t-butoxide, titanium (IV) ethoxide, titanium (IV) i-propoxide, titanium (IV) isobutoxide, Titanium (IV) isopropoxide and the like can be preferably used.
また、ジオールとしては、エチレングリコール、１，２−プロパンジオール、１，３−プロパンジオール、１，２−ブタンジオール、２，３−ブタンジオール、１，３−ブタンジオール、１，２−ペンタンジオール、２−メチル−２，４−ペンタンジオール 等を好適に使用することができる。 Examples of the diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 2,3-butanediol, 1,3-butanediol, and 1,2-pentanediol. 2-methyl-2,4-pentanediol and the like can be preferably used.
実施例に後述するように、本発明製造方法で製造される酸化チタンは、球状の形状を備えたものである。また、製造過程で得られる酸化チタン前駆体もまた、球状の形状を備えたものである。これは上述のとおり、前駆体生成過程Ｐ２で生成した極めて微細な酸化チタン前駆体（チタンジオレート）３５を熱処理過程Ｐ３で熱分解することで粒子成長が抑制されることによるものである。 As will be described later in Examples, the titanium oxide produced by the production method of the present invention has a spherical shape. In addition, the titanium oxide precursor obtained in the manufacturing process also has a spherical shape. As described above, this is because particle growth is suppressed by thermally decomposing the very fine titanium oxide precursor (titanium diolate) 35 generated in the precursor generation process P2 in the heat treatment process P3.
図Ｐ２は、本発明の酸化チタン製造方法の別の構成を示すフロー図である。図示するように本製造方法は、前駆体生成過程Ｐ２にて得られた酸化チタン前駆体３５を水中捕集するものとし、さらに熱処理過程Ｐ３を、水中捕集された酸化チタン前駆体３５を蒸発乾固する蒸発乾固過程Ｐ３Ａと、蒸発乾固した酸化チタン前駆体３８を焼成する焼成過程Ｐ３Ｂとから構成するものとすることができる。 FIG. P2 is a flowchart showing another configuration of the titanium oxide production method of the present invention. As shown in the drawing, in this manufacturing method, the titanium oxide precursor 35 obtained in the precursor generation process P2 is collected in water, and the heat treatment process P3 is further evaporated in the titanium oxide precursor 35 collected in water. It can be composed of an evaporation / drying process P3A for drying and a baking process P3B for baking the evaporated and dried titanium oxide precursor 38.
かかる構成により本フローによれば、前駆体生成過程Ｐ２にて得られた酸化チタン前駆体３５は水中捕集され、次いで熱処理過程Ｐ３中の蒸発乾固過程Ｐ３Ａにおいて酸化チタン前駆体３５は蒸発乾固処理され、次いで焼成過程Ｐ３Ｂにおいて蒸発乾固した酸化チタン前駆体３８が焼成されることによって、最終的にアナターゼ型酸化チタン５０が製造される。なお、焼成過程Ｐ３Ｂにおいては、焼成温度その他適宜の焼成条件を用いることができる。 With this configuration, according to this flow, the titanium oxide precursor 35 obtained in the precursor generation process P2 is collected in water, and then the titanium oxide precursor 35 is evaporated and dried in the evaporation and drying process P3A in the heat treatment process P3. The anatase-type titanium oxide 50 is finally produced by firing the titanium oxide precursor 38 that has been solid-treated and then evaporated and dried in the firing step P3B. In the firing process P3B, a firing temperature or other appropriate firing conditions can be used.
また、熱処理過程Ｐ３を構成する蒸発乾固過程Ｐ３Ａにおいては、適宜の蒸発乾固用の温度による処理を採用することができるが、所定温度による温風乾燥あるいは熱風乾燥処理が効率的かつ便利である。たとえば設定温度１５０℃とした乾燥機にて蒸発乾固処理した場合は、この処理だけでアナターゼ型酸化チタンを生成することができる。つまり本発明製造方法によれば、１５０℃以下の低温加熱でアナターゼ型酸化チタンを生成可能である。 In addition, in the evaporation / drying process P3A constituting the heat treatment process P3, processing at an appropriate evaporation / drying temperature can be adopted, but warm air drying or hot air drying processing at a predetermined temperature is efficient and convenient. is there. For example, when the evaporating and drying process is performed with a dryer having a set temperature of 150 ° C., anatase-type titanium oxide can be generated only by this process. That is, according to the production method of the present invention, anatase-type titanium oxide can be produced by low-temperature heating at 150 ° C. or lower.
なおまた、たとえば温風・熱風ではない低温の風による送風処理、あるいは減圧乾燥など、蒸発乾固過程を熱処理を用いずに別の手段によって蒸発乾固処理をなす過程とすることも、本発明からは除外されない。つまり、熱処理過程Ｐ３から蒸発乾固過程を外して、独立した過程とする構成もまた、本発明の範囲内である。 In addition, for example, the evaporating / drying process may be a process of evaporating / drying by another means without using a heat treatment, such as blowing with a low-temperature air that is not hot air or hot air, or drying under reduced pressure. Is not excluded. In other words, a configuration in which the evaporation to dryness process is removed from the heat treatment process P3 and is made an independent process is also within the scope of the present invention.
上述の本発明製造方法により、球状の形態を備えた酸化チタンを製造することができる。実施例に後述するとおり、本発明酸化チタンの有する球状の形態は、粒径２０ｎｍ以下の一次粒子によって構成されたものである。そして本発明においては、比表面積がＤｅｇｕｓｓａ（登録商標）社製Ｐ２５酸化チタンの３倍以上、あるいは平均細孔径が１０ｎｍ以下かつ細孔径分布がＤｅｇｕｓｓａ（登録商標）社製Ｐ２５酸化チタンよりも均一、またはその双方を兼ね備えた酸化チタンを、提供することができる。 Titanium oxide having a spherical shape can be produced by the production method of the present invention described above. As described later in Examples, the spherical form of the titanium oxide of the present invention is composed of primary particles having a particle size of 20 nm or less. In the present invention, the specific surface area is 3 times or more of P25 titanium oxide manufactured by Degussa (registered trademark), or the average pore diameter is 10 nm or less and the pore size distribution is more uniform than P25 titanium oxide manufactured by Degussa (registered trademark). Or the titanium oxide which has both can be provided.
かかる特徴により本発明酸化チタンは、アセトアルデヒド分解活性がＤｅｇｕｓｓａ（登録商標）社製Ｐ２５酸化チタンよりも高いものとして得ることができ、さらに、可視領域に吸収を示す可視光応答性の酸化チタンとして得ることもできる。したがって本酸化チタンは、優れて高活性な光触媒機能を備えた光触媒材料であり、高活性の光触媒を実現することができる。 Due to such characteristics, the titanium oxide of the present invention can be obtained as having acetaldehyde-decomposing activity higher than that of P25 titanium oxide manufactured by Degussa (registered trademark), and further obtained as visible light-responsive titanium oxide that absorbs in the visible region. You can also. Accordingly, the present titanium oxide is a photocatalytic material having an excellent and highly active photocatalytic function, and can realize a highly active photocatalyst.
また本発明酸化チタンは、光触媒材料のみならず、色素増感太陽電池の光電極材料としても優れたものである。すなわち本酸化チタンは、起電力がＰｅｃｃｅｌｌ（登録商標）社製チタンペーストよりも高いという特性をも備えるためである。これにより、本酸化チタンを用いて色素増感太陽電池の光電極を実現することができる。 The titanium oxide of the present invention is excellent not only as a photocatalyst material but also as a photoelectrode material for a dye-sensitized solar cell. That is, this titanium oxide also has the characteristic that the electromotive force is higher than that of a Peccell (registered trademark) titanium paste. Thereby, the photoelectrode of a dye-sensitized solar cell is realizable using this titanium oxide.
以上、酸化チタン製造に関して述べた本発明手法は、チタン以外の金属アルコキシドにも適用可能である。すなわち、アルミニウム、ジルコニウム、スズ、亜鉛、ケイ素、鉄などの金属アルコキシドとジオールとの組み合わせによって、金属ジオレートの生成とその熱分解による酸化物を生成することができる。つまり本発明は、「ジオールおよび金属アルコキシドを気化させる気化過程と、気化したジオールおよび金属アルコキシドを気相中で反応させて酸化物前駆体を生成する前駆体生成過程と、生成した酸化物前駆体を熱処理して酸化物を得る熱処理過程とを備えてなる、酸化物製造方法」として一般化することができ、今後さまざまな製品・分野に応用可能な原理である。 As described above, the method of the present invention described regarding titanium oxide production can be applied to metal alkoxides other than titanium. That is, a combination of a metal alkoxide such as aluminum, zirconium, tin, zinc, silicon, and iron and a diol can generate a metal diolate and an oxide by thermal decomposition thereof. That is, the present invention relates to "a vaporization process for vaporizing a diol and a metal alkoxide, a precursor generation process for generating an oxide precursor by reacting the vaporized diol and metal alkoxide in a gas phase, and an oxide precursor generated. It can be generalized as an “oxide manufacturing method comprising a heat treatment process for obtaining an oxide by heat treatment”, and is a principle that can be applied to various products and fields in the future.
本発明の実施例について説明するが、本発明がかかる実施例に限定されるものではない。なお、本発明酸化チタンを得るための研究開発過程の概要を述べることで、実施例の説明とする。
＜１．実験方法＞
１．１ 光触媒調製方法：
１．１．１ ＣＶＤ法による酸化チタンの合成
図Ｐ３は、酸化チタン合成方法を示す説明図である。図示するように、オルトチタン酸テトラエチル（以下、ＴＥＯＴ）および１，３−ブタンジオール（以下、１３ＢＤ）をそれぞれガラス製容器に注入し、窒素ガスをそれぞれ３００ｍｌ／ｍｉｎ導入してバブリングさせた。ＴＥＯＴ、１３ＢＤのガラス製容器を１６０℃に加熱することによって、原料を気化させて管状炉内のガラス製反応管へ導入した。なお、ＴＥＯＴ、１３ＢＤの反応管への導入量は、窒素ガスの流量および加熱温度によって調整することができる。なおまた、気化過程においては、減圧下における気化など、加熱以外の方法により原料を気化させることも本発明から除外されない。
Examples of the present invention will be described, but the present invention is not limited to such examples. In addition, it is set as description of an Example by giving the outline | summary of the research and development process for obtaining this invention titanium oxide.
<1. Experimental method>
1.1 Photocatalyst preparation method:
1.1.1 Synthesis of Titanium Oxide by CVD Method FIG. P3 is an explanatory view showing a titanium oxide synthesis method. As shown in the figure, tetraethyl orthotitanate (hereinafter referred to as TEOT) and 1,3-butanediol (hereinafter referred to as 13BD) were each injected into a glass container, and nitrogen gas was introduced at 300 ml / min for bubbling. By heating a TEOT, 13BD glass container to 160 ° C., the raw material was vaporized and introduced into a glass reaction tube in a tubular furnace. The amount of TEOT and 13BD introduced into the reaction tube can be adjusted by the flow rate of nitrogen gas and the heating temperature. In the vaporization process, vaporizing the raw material by a method other than heating, such as vaporization under reduced pressure, is not excluded from the present invention.
気化したＴＥＯＴと１３ＢＤは、キャリアーガスとともに２１０℃に加熱した反応管に導かれ、気相中で球状のチタンジオレート（酸化チタン前駆体）を生成した。生成したチタンジオレートは吸引ポンプで吸引し、水中でバブリングさせることによって粒子を水中に分散させて捕集した。次いで粒子を含んだ溶液を１５０℃の乾燥機中で蒸発乾固させた後、空気中５００℃で２ｈ熱処理して酸化チタンを得た。 The vaporized TEOT and 13BD were introduced into a reaction tube heated to 210 ° C. together with a carrier gas, and spherical titanium diolate (titanium oxide precursor) was generated in the gas phase. The produced titanium diolate was sucked with a suction pump and bubbled in water to collect particles dispersed in water. Next, the solution containing the particles was evaporated to dryness in a dryer at 150 ° C., and then heat-treated at 500 ° C. for 2 hours in air to obtain titanium oxide.
１．１．２ ゾル‐ゲル（ＳＧ）法による酸化チタンの合成（比較例）
１ｍｏｌのＴＥＯＴに対して１０倍ｍｏｌの１３ＢＤにＴＥＯＴを滴下し、室温で強く撹拌した。その後、水を加えてさらに撹拌した後、１５０℃で蒸発乾固、５００℃で２ｈ焼成して酸化チタンを得た。
1.1.2 Synthesis of Titanium Oxide by Sol-Gel (SG) Method (Comparative Example)
TEOT was dripped into 13BD of 10-fold mol with respect to 1 mol TEOT, and it stirred vigorously at room temperature. Thereafter, water was added and further stirred, and then evaporated to dryness at 150 ° C. and calcined at 500 ° C. for 2 hours to obtain titanium oxide.
１．２ 光触媒活性評価
図Ｐ４は、合成した酸化チタンの触媒性能評価方法を示す説明図である。図示するように、２０ｄｍ３のガラス製デシケーター内に、１００ｍｇの酸化チタンを担持した７５ｍｍ×７５ｍｍのシリカ繊維を設置した。評価の手順は次のとおりである。まずデシケーター内に試料を設置後、３０ｍｉｎ紫外線（東芝製ブラックライト、ＦＬ４ＢＬＢ、ピーク波長３５２ｎｍ、紫外線強度４ｍＷ／ｃｍ２）を照射した。次いで、空気でデシケーター内を置換した後、温度２５℃、湿度１３ｇ／ｍ３に調整した。デシケーターにアセトアルデヒドを２０ｐｐｍ注入し、吸着平衡に達した後、紫外線を照射し、濃度の経時変化をＩＮＮＯＶＡ Ａｉｒ Ｔｅｃｈ Ｉｎｓｔｒｕｍｅｎｔｓ社製光音響マルチガスモニター１３１４型を用いて分析した。アセトアルデヒドの分解は一次反応であることから、アセトアルデヒドの濃度変化より速度定数を算出し、光触媒活性の比較に用いた。
1.2 Photocatalytic Activity Evaluation FIG. P4 is an explanatory diagram showing a method for evaluating the catalytic performance of the synthesized titanium oxide. As shown in the drawing, a 75 mm × 75 mm silica fiber carrying 100 mg of titanium oxide was placed in a 20 dm 3 glass desiccator. The evaluation procedure is as follows. First, a sample was placed in a desiccator, and then irradiated with ultraviolet rays (Toshiba Black Light, FL4BLB, peak wavelength 352 nm, ultraviolet intensity 4 mW / cm 2 ) for 30 minutes. Subsequently, after the inside of the desiccator was replaced with air, it was adjusted to a temperature of 25 ° C. and a humidity of 13 g / m 3 . After 20 ppm of acetaldehyde was injected into the desiccator and the adsorption equilibrium was reached, ultraviolet irradiation was performed, and the change in concentration over time was analyzed using a photoacoustic multi-gas monitor 1314 manufactured by INNOVA Air Tech Instruments. Since decomposition of acetaldehyde is a first order reaction, a rate constant was calculated from a change in concentration of acetaldehyde and used for comparison of photocatalytic activity.
２．結果と考察
図１は、ＣＶＤ法により調製した酸化チタン前駆体と熱処理後の試料のＸＲＤパターンを示すグラフである。反応管出口で捕集した試料（ａ）は、チタンジオレートに特有な２θ＝８°と１０°付近にシャープなピークが認められた。このことから、ＣＶＤ反応装置内の気相中でＴＥＯＴとＢＤからチタンジオレートが生成することが確認できた。反応管で生成したチタンジオレートは、吸引ポンプで吸引し、水中バブリングさせて捕集した。
2. Results and Discussion FIG. 1 is a graph showing an XRD pattern of a titanium oxide precursor prepared by a CVD method and a sample after heat treatment. In the sample (a) collected at the outlet of the reaction tube, sharp peaks were recognized at 2θ = 8 ° and around 10 °, which are characteristic of titanium geolate. From this, it was confirmed that titanium geolate was produced from TEOT and BD in the gas phase in the CVD reactor. Titanium diolate produced in the reaction tube was sucked with a suction pump and collected by bubbling in water.
このチタンジオレートを含む水溶液を１５０℃で蒸発乾固させた試料（ｂ）では、チタンジオレートに特有なピークは認められず、アナターゼ型酸化チタンとして存在していた。アナターゼ型酸化チタンは通常４００℃以上の温度で熱処理しなければ生成しないが、本発明のＣＶＤ法によりチタンジオレートを経由した方法では、わずか１５０℃でアナターゼ型の酸化チタンが生成した。また、（ｂ）を５００℃で焼成した試料（ｃ）は、熱処理によって結晶化が進行したアナターゼ型酸化チタンとなっていた。 In the sample (b) obtained by evaporating and drying this aqueous solution containing titanium diolate at 150 ° C., a peak peculiar to titanium diolate was not observed, and it existed as anatase type titanium oxide. Anatase-type titanium oxide is usually not produced unless it is heat-treated at a temperature of 400 ° C. or higher, but anatase-type titanium oxide was produced at a temperature of only 150 ° C. by the CVD method of the present invention via titanium geolate. Further, the sample (c) obtained by baking (b) at 500 ° C. was anatase-type titanium oxide in which crystallization progressed by heat treatment.
図２は、ＳＧ法によって調製した酸化チタン前駆体と熱処理後の試料のＸＲＤパターンを示すグラフである。ＴＥＯＴと１３ＢＤを混合して撹拌した試料を乾燥した試料（ａ）は、２θ＝８°と１０°付近にチタンジオレート特有のシャープなピークが認められた。チタンジオレート生成後に水を加えてＣＶＤ法における水中捕集と同様の操作を行い蒸発乾固した試料（ｂ）では、２θ＝８°と１０°に弱いチタンジオレートのピークは見られるが、図１における（ｂ）のようなアナターゼ型酸化チタンの生成は認められなかった。（ｂ）を５００℃で焼成した試料（ｃ）では、アナターゼ型のピークが観察された。以上の結果から、ＣＶＤ法で生成したチタンジオレートは、水中捕集後わずか１５０℃の低温でアナターゼ型の酸化チタンを生じることが明らかとなった。 FIG. 2 is a graph showing an XRD pattern of a titanium oxide precursor prepared by the SG method and a sample after heat treatment. In the sample (a) obtained by drying a sample obtained by mixing and stirring TEOT and 13BD, sharp peaks peculiar to titanium geolate were observed at 2θ = 8 ° and around 10 °. In the sample (b) obtained by adding water after the production of titanium geolate and evaporating to dryness by performing the same operation as underwater collection in the CVD method, peaks of titanium geolate weak at 2θ = 8 ° and 10 ° are seen, Formation of anatase-type titanium oxide as shown in (b) in FIG. 1 was not observed. In sample (c) obtained by baking (b) at 500 ° C., an anatase type peak was observed. From the above results, it was clarified that titanium geolate produced by the CVD method produces anatase-type titanium oxide at a low temperature of only 150 ° C. after collection in water.
図３（ａ）は、ＣＶＤ法で調製した酸化チタンのＳＥＭ像写真である。また、図３（ｂ）は、図３（ａ）で観察された球状粒子の表面構造のＳＥＭ像写真、図４は、ＳＧ法で調製した酸化チタンのＳＥＭ像写真である。図３（ａ）に示すようにＣＶＤ法で調製された酸化チタンは、直径数百ｎｍから数μｍに及ぶ広い範囲の粒子径を示していた。また、図３（ｂ）に示したように、粒子表面を拡大して観察したところ、球状粒子は１０〜２０ｎｍの一次粒子によって構成されていることが確認された。一方、図４に示したＳＧ法の酸化チタンでは球状粒子は観察されず、１００ｎｍ程度の一次粒子によって構成された数百μｍに及ぶ凝集粒子として存在していた。 FIG. 3A is a SEM image photograph of titanium oxide prepared by the CVD method. 3B is a SEM image photograph of the surface structure of the spherical particles observed in FIG. 3A, and FIG. 4 is a SEM image photograph of titanium oxide prepared by the SG method. As shown in FIG. 3A, the titanium oxide prepared by the CVD method showed a wide range of particle diameters ranging from several hundred nm to several μm. In addition, as shown in FIG. 3B, when the particle surface was enlarged and observed, it was confirmed that the spherical particles were composed of primary particles of 10 to 20 nm. On the other hand, in the SG method titanium oxide shown in FIG. 4, spherical particles were not observed, and existed as aggregated particles extending over several hundred μm composed of primary particles of about 100 nm.
ＣＶＤ法、ＳＧ法およびＤｅｇｕｓｓａ（登録商標）社製Ｐ２５について、窒素吸着法によって細孔径分布、比表面積、全細孔容積および平均細孔径を測定した。
図５は、各製法による酸化チタンの細孔径分布を示すグラフである。図示するように、ＣＶＤ法で調製した試料はＳＧ法によるものやＰ２５に比べて、はるかに小さい７．４ｎｍをピークとした比較的均一な細孔径分布を示した。一方、ＳＧ法の酸化チタンは、１５〜１００ｎｍ、Ｐ２５は３０〜２００ｎｍにかけて幅広い細孔径分布を示した。
For the CVD method, the SG method, and P25 manufactured by Degussa (registered trademark), the pore size distribution, specific surface area, total pore volume, and average pore size were measured by a nitrogen adsorption method.
FIG. 5 is a graph showing the pore size distribution of titanium oxide by each production method. As shown in the figure, the sample prepared by the CVD method showed a relatively uniform pore size distribution having a peak at a much smaller 7.4 nm than that by the SG method or P25. On the other hand, SG method titanium oxide showed a wide pore size distribution from 15 to 100 nm and P25 from 30 to 200 nm.
ＣＶＤ法の酸化チタンは、１９０ｍ２／ｇという極めて高い比表面積と、１０ｎｍ程度の小さな平均細孔径を示した。この比表面積は、ＳＧ法やＰ２５の３倍以上という著しく高い比表面積である。このように、気相中でチタンジオレートを生成するＣＶＤ法による酸化チタンが、同一原料を用いた液相反応であるＳＧ法によるものとは、大きく異なる物性を示すものであることが明らかとなった。 CVD titanium oxide showed a very high specific surface area of 190 m 2 / g and a small average pore diameter of about 10 nm. This specific surface area is a remarkably high specific surface area of 3 times or more of SG method or P25. Thus, it is clear that the titanium oxide by the CVD method that generates titanium geolate in the gas phase exhibits significantly different physical properties from those by the SG method, which is a liquid phase reaction using the same raw material. became.
表２に、本発明に係るＣＶＤ法酸化チタン、従来技術であるＳＧ法およびＰ２５について、アセトアルデヒド分解速度定数を示す。ＣＶＤ法による酸化チタンは、ＳＧ法やＰ２５に比べておよそ１．２倍ものアセトアルデヒド分解速度を有する、優れた光触媒となることが明らかとなった。 Table 2 shows the acetaldehyde decomposition rate constants for the CVD titanium oxide according to the present invention, the SG method and P25, which are conventional techniques. It has been clarified that titanium oxide by CVD method is an excellent photocatalyst having an acetaldehyde decomposition rate about 1.2 times that of SG method or P25.
図６は、各製法による酸化チタンのＵＶ−Ｖｉｓ．反射スペクトルを示すグラフである。図示するようにいずれの酸化チタン試料も、４００ｎｍ以下の紫外領域で強い吸収が見られた。本発明に係るＣＶＤ法で調製した試料では、他の従来製法によるものと比較して４００〜５００ｎｍの可視領域において吸収が認められ、本発明製法により得られる酸化チタンが可視光応答性光触媒であることが明らかとなった。なお、ＳＧ法による試料でもわずかに可視領域に吸収が認められたが、本発明に係るＣＶＤ法による試料の方が大きな吸収を示した。また、Ｐ２５では可視領域における吸収が認められなかった。 FIG. 6 shows UV-Vis. It is a graph which shows a reflection spectrum. As shown in the figure, any of the titanium oxide samples showed strong absorption in the ultraviolet region of 400 nm or less. In the sample prepared by the CVD method according to the present invention, absorption is observed in the visible region of 400 to 500 nm as compared with that by other conventional production methods, and the titanium oxide obtained by the present production method is a visible light responsive photocatalyst. It became clear. In addition, although the absorption by the SG method was slightly recognized in the visible region, the sample by the CVD method according to the present invention showed a larger absorption. In P25, no absorption in the visible region was observed.
３．色素増感太陽電池の光電極への応用試験
本発明に係るＣＶＤ法による酸化チタンについて、色素増感太陽電池の光電極への応用を試みた。Ｐｅｃｃｅｌｌ（登録商標）社製の簡易色素増感太陽電池実験キット（ＰＥＣ−ＴＯＭ０２）を用いて、２７Ｗの蛍光灯を光源に起電力の評価を行った。その結果を表３に示す。
3. Application Test of Dye-Sensitized Solar Cell to Photoelectrode An attempt was made to apply the titanium oxide produced by the CVD method according to the present invention to a photoelectrode of a dye-sensitized solar cell. Using a simple dye-sensitized solar cell experiment kit (PEC-TOM02) manufactured by Peccell (registered trademark), an electromotive force was evaluated using a 27 W fluorescent lamp as a light source. The results are shown in Table 3.
なおＣＶＤ法酸化チタンおよびＰ２５については、粉末試料に色素を含浸させて透明電極膜に密着させて測定に供した。表に示すようにＣＶＤ法による酸化チタンは、Ｐ２５に比べて約２倍、Ｐｅｃｃｅｌｌ（登録商標）社製チタンペーストと比較しても高い起電力を発生することが明らかとなった。すなわち本発明に係る酸化チタンは、通常の紫外光の他、可視光も利用可能な光触媒であるばかりか、色素増感太陽電池光電極としても応用可能な、優れた材料であることが明らかとなった。 For CVD titanium oxide and P25, a powder sample was impregnated with a dye and adhered to a transparent electrode film for measurement. As shown in the table, it has been clarified that titanium oxide produced by the CVD method generates a high electromotive force about twice as much as that of P25, even when compared with titanium paste manufactured by Peccell (registered trademark). That is, the titanium oxide according to the present invention is not only a photocatalyst that can use visible light in addition to normal ultraviolet light, but is also an excellent material that can be applied as a dye-sensitized solar cell photoelectrode. became.
４．まとめ＿ＣＶＤ法による酸化チタンの特徴
本研究開発の成果は次のとおりである。
〔１〕チタンアルコキシドとジオールから生成する球状の酸化チタン前駆体（チタンジオレート）を経由した球状酸化チタンが得られた。
〔２〕得られた球状酸化チタンは、数十ｎｍの一次粒子によって構成されたものだった。
〔３〕１５０℃という低温加熱で、アナターゼ型酸化チタンを生成できた。
〔４〕得られた酸化チタンは、市販の高性能光触媒であるところのＰ２５の３倍を超える大きな比表面積を有するものだった。
4). Summary _Characteristics of titanium oxide by CVD method The results of this research and development are as follows.
[1] Spherical titanium oxide was obtained via a spherical titanium oxide precursor (titanium diolate) produced from titanium alkoxide and diol.
[2] The obtained spherical titanium oxide was composed of primary particles of several tens of nm.
[3] Anatase-type titanium oxide could be produced by heating at a low temperature of 150 ° C.
[4] The obtained titanium oxide had a large specific surface area exceeding 3 times P25 which is a commercially available high-performance photocatalyst.
〔５〕さらに、Ｐ２５等よりも均一な細孔径分布と、１０ｎｍ程度という小さな平均細孔径を有するものだった。
〔６〕また、Ｐ２５に比べて１．２倍もの高いアセトアルデヒド分解活性を備えたものだった。
〔７〕しかも、可視領域に吸収を示す可視光応答性酸化チタンであった。
〔８〕加えて本研究開発で得られた酸化チタンは、従来の材料にも全く遜色なく色素増感太陽電池光電極への適用が充分に可能な酸化チタン材料であった。
[5] Further, it had a more uniform pore size distribution than P25 and an average pore size as small as about 10 nm.
[6] Further, it had an acetaldehyde-degrading activity 1.2 times higher than that of P25.
[7] In addition, it was a visible light responsive titanium oxide exhibiting absorption in the visible region.
[8] In addition, the titanium oxide obtained in this research and development was a titanium oxide material that was completely comparable to conventional materials and could be sufficiently applied to a dye-sensitized solar cell photoelectrode.
５．補足＿酸化チタン調製条件の検討
本研究開発の初期段階において、ＴＥＯＴ、１３ＢＤに対する窒素供給量や原料気化部、気体加熱部、反応管の温度をそれぞれ変化させて、酸化チタン調製に適した条件を検討した結果を、補足的に記載する。
図７−１、図７−２、および図７−３は、酸化チタン調製最適条件検討結果を示すものであり、それぞれ管状炉（反応管）の温度、原料加熱部の温度、および気体加熱部の温度についての検討結果を示す。また図７−４は、酸化チタン調製最適条件検討結果をまとめた説明図である。これらに図示するように、本検討において最も高い光触媒活性を示す調製条件は、窒素供給量０．３ｄｍ３／ｍｉｎ、原料加熱部温度１７０℃、管状炉（反応管）温度２１０℃であった。
5. Supplementary_Examination of Titanium Oxide Preparation Conditions In the initial stage of this research and development, the nitrogen supply amount for TEOT and 13BD, the raw material vaporization part, the gas heating part, and the temperature of the reaction tube were changed to set conditions suitable for titanium oxide preparation. The result of examination is described supplementarily.
7-1, FIG. 7-2, and FIG. 7-3 show the optimum conditions for preparing titanium oxide, and show the temperature of the tubular furnace (reaction tube), the temperature of the raw material heating unit, and the gas heating unit, respectively. The examination result about the temperature of is shown. Moreover, FIG. 7-4 is explanatory drawing which put together the titanium oxide preparation optimal condition examination result. As shown in these figures, the preparation conditions exhibiting the highest photocatalytic activity in this study were a nitrogen supply amount of 0.3 dm 3 / min, a raw material heating part temperature of 170 ° C., and a tubular furnace (reaction tube) temperature of 210 ° C.
なお、検討した範囲では、管状炉（反応管）の温度を１９０℃、２１０℃、２３０℃とした場合に従来技術（ＳＧ法、Ｐ２５）よりも速度定数が高く、したがって、少なくとも１９０〜２３０℃の温度範囲では、従来技術よりも高い光触媒活性を有する酸化チタンが得られると判断された。また、原料加熱部の温度を１７０℃、２００℃とした場合に従来技術（ＳＧ法、Ｐ２５）よりも速度定数が高く、したがって、少なくとも１７０〜２００℃の温度範囲では、従来技術よりも高い光触媒活性を有する酸化チタンが得られると判断された。また、気体加熱部の温度を２００℃とした場合に従来技術（ＳＧ法、Ｐ２５）よりも速度定数が高く、したがって２００℃程度で、従来技術よりも高い光触媒活性を有する酸化チタンが得られると判断された。 In the examined range, when the temperature of the tubular furnace (reaction tube) is 190 ° C., 210 ° C., and 230 ° C., the rate constant is higher than that of the prior art (SG method, P25), and therefore at least 190 to 230 ° C. In this temperature range, it was determined that a titanium oxide having a photocatalytic activity higher than that of the prior art can be obtained. Further, when the temperature of the raw material heating part is set to 170 ° C. and 200 ° C., the rate constant is higher than that of the conventional technique (SG method, P25), and therefore, at least in the temperature range of 170 to 200 ° C., the photocatalyst is higher than that of the conventional technique. It was determined that an active titanium oxide was obtained. Further, when the temperature of the gas heating unit is 200 ° C., the rate constant is higher than that of the conventional technique (SG method, P25), and therefore, when titanium oxide having a photocatalytic activity higher than that of the conventional technique is obtained at about 200 ° C. It was judged.
また図７−５は、本発明に係るＣＶＤ法酸化チタン、従来技術であるＳＧ法およびＰ２５によるアセトアルデヒド分解試験における、アセトアルデヒド濃度経時変化を示すグラフであり、図７−１等と同様、本研究開発の初期段階において得られた結果である。本発明に係る酸化チタンが従来の製法によるものよりも速くアセトアルデヒドを分解できる優れた光触媒となることが、すでに初期段階において明らかになっていたことを示すものである。 FIG. 7-5 is a graph showing the acetaldehyde concentration change over time in the CVD method titanium oxide according to the present invention, the acetaldehyde decomposition test by the conventional SG method and P25, and this study is similar to FIG. This is the result obtained in the early stage of development. The fact that the titanium oxide according to the present invention is an excellent photocatalyst capable of decomposing acetaldehyde faster than that according to the conventional production method has already been clarified in the initial stage.
本発明の酸化チタン製造方法等によれば、簡便かつ安価な方法によって連続的に高活性な酸化チタン粉末の合成が可能になる。また本発明に係る酸化チタンは、通常の紫外光の他、可視光も利用可能な実用性の高い高活性光触媒を提供できるばかりか、色素増感太陽電池光電極としても極めて有望な材料である。したがって、光触媒ならびに色素増感太陽電池製造およびこれに関連する全産業分野において、利用性が高い発明である。 According to the titanium oxide production method and the like of the present invention, a highly active titanium oxide powder can be continuously synthesized by a simple and inexpensive method. Further, the titanium oxide according to the present invention can provide a highly active photocatalyst with high practicality capable of using visible light in addition to normal ultraviolet light, and is also a very promising material as a dye-sensitized solar cell photoelectrode. . Therefore, the invention is highly useful in the production of photocatalysts and dye-sensitized solar cells and in all industrial fields related thereto.
１…ジオール
２…チタンアルコキシド
１３…気化したジオール
２４…気化したチタンアルコキシド
３５…酸化チタン前駆体
３８…蒸発乾固した酸化チタン前駆体
５０…アナターゼ型酸化チタン
Ｐ１…気化過程
Ｐ２…前駆体生成過程
Ｐ３…熱処理過程
Ｐ３Ａ…蒸発乾固過程
Ｐ３Ｂ…焼成過程
DESCRIPTION OF SYMBOLS 1 ... Diol 2 ... Titanium alkoxide 13 ... Evaporated diol 24 ... Evaporated titanium alkoxide 35 ... Titanium oxide precursor 38 ... Evaporated and dried titanium oxide precursor 50 ... Anatase type titanium oxide P1 ... Evaporation process P2 ... Precursor formation process P3 ... Heat treatment process P3A ... Evaporation-drying process P3B ... Firing process
Claims (17)
A vaporization process for vaporizing a diol and a metal alkoxide, a precursor generation process for reacting the vaporized diol and metal alkoxide in a gas phase to generate an oxide precursor, and a heat treatment of the generated oxide precursor to produce an oxide And a heat treatment process for obtaining an oxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012170721A JP2014031281A (en) | 2012-08-01 | 2012-08-01 | Titanium oxide production method, titanium oxide, photocatalyst, and photoelectrode of dye-sensitized solar cell |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012170721A JP2014031281A (en) | 2012-08-01 | 2012-08-01 | Titanium oxide production method, titanium oxide, photocatalyst, and photoelectrode of dye-sensitized solar cell |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2014031281A true JP2014031281A (en) | 2014-02-20 |
Family
ID=50281429
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2012170721A Pending JP2014031281A (en) | 2012-08-01 | 2012-08-01 | Titanium oxide production method, titanium oxide, photocatalyst, and photoelectrode of dye-sensitized solar cell |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2014031281A (en) |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3756841A (en) * | 1971-06-30 | 1973-09-04 | Du Pont | Chloride tio2 pigments suited for high solids low viscosity slurries |
| JPH01252508A (en) * | 1987-12-17 | 1989-10-09 | Mitsubishi Electric Corp | Production of oxide superconductor |
| JPH1111981A (en) * | 1997-06-16 | 1999-01-19 | Central Glass Co Ltd | Formation of titanium oxide |
| JP2003252627A (en) * | 2002-02-27 | 2003-09-10 | Toshiba Corp | Method of manufacturing particle and manufacturing device for the same |
| JP2004196618A (en) * | 2002-12-19 | 2004-07-15 | Asahi Glass Co Ltd | Method for manufacturing titanium oxide membrane |
| JP2004331427A (en) * | 2003-05-01 | 2004-11-25 | Fujikura Ltd | Titanium oxide particle |
| JP2006083363A (en) * | 2004-04-26 | 2006-03-30 | Showa Denko Kk | Coating material and use of the same |
| JP2006089297A (en) * | 2004-09-21 | 2006-04-06 | Shiseido Co Ltd | Aegagropila-shaped porous titanium oxide having high photocatalytic activity |
| JP2006224000A (en) * | 2005-02-17 | 2006-08-31 | Institute Of National Colleges Of Technology Japan | Method of synthesizing photocatalyst and photocatalyst precursor |
| WO2011029145A1 (en) * | 2009-09-10 | 2011-03-17 | Monash University | Method of manufacturing mesoscopic solar cells |
| JP2012096965A (en) * | 2010-11-02 | 2012-05-24 | Toyohashi Univ Of Technology | Porous titanium oxide, hydrogen detector, methods for producing them, hydrogen sensor and photoelectric conversion element |
-
2012
- 2012-08-01 JP JP2012170721A patent/JP2014031281A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3756841A (en) * | 1971-06-30 | 1973-09-04 | Du Pont | Chloride tio2 pigments suited for high solids low viscosity slurries |
| JPH01252508A (en) * | 1987-12-17 | 1989-10-09 | Mitsubishi Electric Corp | Production of oxide superconductor |
| JPH1111981A (en) * | 1997-06-16 | 1999-01-19 | Central Glass Co Ltd | Formation of titanium oxide |
| JP2003252627A (en) * | 2002-02-27 | 2003-09-10 | Toshiba Corp | Method of manufacturing particle and manufacturing device for the same |
| JP2004196618A (en) * | 2002-12-19 | 2004-07-15 | Asahi Glass Co Ltd | Method for manufacturing titanium oxide membrane |
| JP2004331427A (en) * | 2003-05-01 | 2004-11-25 | Fujikura Ltd | Titanium oxide particle |
| JP2006083363A (en) * | 2004-04-26 | 2006-03-30 | Showa Denko Kk | Coating material and use of the same |
| JP2006089297A (en) * | 2004-09-21 | 2006-04-06 | Shiseido Co Ltd | Aegagropila-shaped porous titanium oxide having high photocatalytic activity |
| JP2006224000A (en) * | 2005-02-17 | 2006-08-31 | Institute Of National Colleges Of Technology Japan | Method of synthesizing photocatalyst and photocatalyst precursor |
| WO2011029145A1 (en) * | 2009-09-10 | 2011-03-17 | Monash University | Method of manufacturing mesoscopic solar cells |
| JP2012096965A (en) * | 2010-11-02 | 2012-05-24 | Toyohashi Univ Of Technology | Porous titanium oxide, hydrogen detector, methods for producing them, hydrogen sensor and photoelectric conversion element |
Non-Patent Citations (2)
| Title |
|---|
| JPN6016016308; ＨＡＳＥＧＡＷＡ， Ａ． ｅｔ ａｌ: 'Ｐｒｅｐａｒａｔｉｏｎ ａｎｄ Ｃｈａｒａｃｔｅｒｉｚａｔｉｏｎ ｏｆ Ｓｑｕａｒｅ Ｒｏｄ ＴｉＯ２ Ｄｅｒｉｖｅｄ ｆｒｏｍ Ｐｙｒｏｌｙｓｉｓ ｏｆ Ｔｉｔａｎｉｕｍ Ａｌｋｏｘｙ-Ｄｉｏｌａｔ' Ｊｏｕｒｎａｌ ｏｆ ｔｈｅ Ｓｏｃｉｅｔｙ ｏｆ Ｉｎｏｒｇａｎｉｃ Ｍａｔｅｒｉａｌｓ， Ｊａｐａｎ Ｖｏｌ．１６， Ｎｏ．３３８, 20090101, ｐ．３７-４３ * |
| JPN6016016310; 長谷川章，外: '角柱状酸化チタンの調製 ： 形態に及ぼす溶媒の影響とその光触媒作用' Ｊｏｕｒｎａｌ ｏｆ ｔｈｅ Ｃｅｒａｍｉｃ Ｓｏｃｉｅｔｙ ｏｆ Ｊａｐａｎ Ｖｏｌ．１１５， Ｎｏ．１３３７, 200701, ｐ．５９-６４ * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wu | Photocatalytic reduction of greenhouse gas CO 2 to fuel | |
| Fan et al. | Solvothermal synthesis of hierarchical TiO2 nanostructures with tunable morphology and enhanced photocatalytic activity | |
| He et al. | Photocatalytic degradation of methyl orange over nitrogen–fluorine codoped TiO2 nanobelts prepared by solvothermal synthesis | |
| Dong et al. | One-step “green” synthetic approach for mesoporous C-doped titanium dioxide with efficient visible light photocatalytic activity | |
| Wang et al. | A simple two-step template approach for preparing carbon-doped mesoporous TiO2 hollow microspheres | |
| TWI382958B (en) | Method for making metal/titania pulp and photocatalyst | |
| Wei et al. | Effect of Pt loading and calcination temperature on the photocatalytic hydrogen production activity of TiO2 microspheres | |
| KR101356117B1 (en) | Organic-inorganic photocatalyst composite and process for producing the same by spray pyrolysis method | |
| Chiodi et al. | Enhanced dopant solubility and visible-light absorption in Cr–N codoped TiO2 nanoclusters | |
| Alosfur et al. | One-step formation of TiO2 hollow spheres via a facile microwave-assisted process for photocatalytic activity | |
| Huang et al. | Highly efficient Zr doped-TiO2/glass fiber photocatalyst and its performance in formaldehyde removal under visible light | |
| Alzahrani et al. | Enhanced visible light response of heterostructured Cr2O3 incorporated two-dimensional mesoporous TiO2 framework for H2 evolution | |
| CN103691415B (en) | High-crystallinity, rule the titania-silica nano-complex of meso-hole structure, preparation method and applications | |
| Wasan Awin et al. | Novel precursor-derived meso-/macroporous TiO2/SiOC nanocomposites with highly stable anatase nanophase providing visible light photocatalytic activity and superior adsorption of organic dyes | |
| Padmini et al. | Mesoporous rutile TiO2: Synthesis, characterization and photocatalytic performance studies | |
| Andersson et al. | Microemulsion-mediated room-temperature synthesis of high-surface-area rutile and its photocatalytic performance | |
| CN109174075A (en) | A kind of rare-earth element modified titanium dioxide nano photocatalysis material and preparation method thereof for photocatalytic degradation VOCs | |
| Guo et al. | Fabrication of N-doped TiO2/activated carbon fiber composites with enhanced photocatalytic activity | |
| Taherinia et al. | Influence of calcination temperature and solvent of titanium precursor on the photocatalytic activity of N-doped TiO 2 nanoparticles in H 2 evolution under visible radiation | |
| Kassahun et al. | Facile low temperature immobilization of N-doped TiO 2 prepared by sol–gel method | |
| Belfaa et al. | Synthesis and characterization of V-doped TiO 2 nanoparticles through polyol method with enhanced photocatalytic activities | |
| Sivakumar et al. | Synthesis of ZnO nanowire and ZnO/CeO2 solid solution nanowire by bio-morphing and its characterization | |
| Meng et al. | Facile synthesis of direct sunlight-driven anatase TiO 2 nanoparticles by in situ modification with trifluoroacetic acid | |
| Yin et al. | Ti 3+-doped TiO 2 hollow sphere with mixed phases of anatase and rutile prepared by dual-frequency atmospheric pressure plasma jet | |
| Niu et al. | Rapid microwave hydrothermal methods synthesis of TiO2 photocatalysts using different sources of materials |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20150516 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20160324 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20160502 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20161027 |