JP5591683B2 - Metal ion-supported titanium oxide particles having an exposed crystal face and method for producing the same - Google Patents
Metal ion-supported titanium oxide particles having an exposed crystal face and method for producing the same Download PDFInfo
- Publication number
- JP5591683B2 JP5591683B2 JP2010291673A JP2010291673A JP5591683B2 JP 5591683 B2 JP5591683 B2 JP 5591683B2 JP 2010291673 A JP2010291673 A JP 2010291673A JP 2010291673 A JP2010291673 A JP 2010291673A JP 5591683 B2 JP5591683 B2 JP 5591683B2
- Authority
- JP
- Japan
- Prior art keywords
- titanium oxide
- oxide particles
- plane
- supported
- ion
- 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.)
- Active
Links
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 title claims description 267
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 title claims description 229
- 239000002245 particle Substances 0.000 title claims description 203
- 239000013078 crystal Substances 0.000 title claims description 43
- 229910052751 metal Inorganic materials 0.000 title claims description 26
- 239000002184 metal Substances 0.000 title claims description 26
- 238000004519 manufacturing process Methods 0.000 title claims description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 93
- 229910052742 iron Inorganic materials 0.000 claims description 58
- 229910001428 transition metal ion Inorganic materials 0.000 claims description 47
- -1 iron ion Chemical class 0.000 claims description 35
- 238000007254 oxidation reaction Methods 0.000 claims description 29
- 239000011941 photocatalyst Substances 0.000 claims description 15
- 230000005284 excitation Effects 0.000 claims description 9
- 229910021645 metal ion Inorganic materials 0.000 claims description 3
- 238000006243 chemical reaction Methods 0.000 description 31
- 239000010936 titanium Substances 0.000 description 30
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 27
- 239000007864 aqueous solution Substances 0.000 description 25
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 22
- 238000002360 preparation method Methods 0.000 description 20
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 18
- 230000001699 photocatalysis Effects 0.000 description 18
- 238000002149 energy-dispersive X-ray emission spectroscopy Methods 0.000 description 14
- 238000006722 reduction reaction Methods 0.000 description 13
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Substances [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 12
- 150000003609 titanium compounds Chemical class 0.000 description 12
- 230000005540 biological transmission Effects 0.000 description 11
- 238000000034 method Methods 0.000 description 11
- 229910052719 titanium Inorganic materials 0.000 description 11
- IKHGUXGNUITLKF-UHFFFAOYSA-N Acetaldehyde Chemical compound CC=O IKHGUXGNUITLKF-UHFFFAOYSA-N 0.000 description 10
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 10
- 239000000460 chlorine Substances 0.000 description 10
- 230000007423 decrease Effects 0.000 description 10
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 9
- 239000003795 chemical substances by application Substances 0.000 description 8
- VCJMYUPGQJHHFU-UHFFFAOYSA-N iron(3+);trinitrate Chemical compound [Fe+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O VCJMYUPGQJHHFU-UHFFFAOYSA-N 0.000 description 8
- 230000006798 recombination Effects 0.000 description 8
- 238000005215 recombination Methods 0.000 description 8
- 238000000926 separation method Methods 0.000 description 8
- 239000000243 solution Substances 0.000 description 8
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 7
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 7
- 239000007795 chemical reaction product Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- 238000010335 hydrothermal treatment Methods 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 6
- 229910052753 mercury Inorganic materials 0.000 description 6
- 229910002092 carbon dioxide Inorganic materials 0.000 description 5
- 239000008367 deionised water Substances 0.000 description 5
- 229910021641 deionized water Inorganic materials 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 150000002500 ions Chemical class 0.000 description 5
- 230000001603 reducing effect Effects 0.000 description 5
- 238000004381 surface treatment Methods 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 4
- 239000004809 Teflon Substances 0.000 description 4
- 229920006362 Teflon® Polymers 0.000 description 4
- 230000003197 catalytic effect Effects 0.000 description 4
- RBTARNINKXHZNM-UHFFFAOYSA-K iron trichloride Chemical compound Cl[Fe](Cl)Cl RBTARNINKXHZNM-UHFFFAOYSA-K 0.000 description 4
- 230000001590 oxidative effect Effects 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 239000012736 aqueous medium Substances 0.000 description 3
- 238000005119 centrifugation Methods 0.000 description 3
- 229910052801 chlorine Inorganic materials 0.000 description 3
- 238000005470 impregnation Methods 0.000 description 3
- YADSGOSSYOOKMP-UHFFFAOYSA-N lead dioxide Inorganic materials O=[Pb]=O YADSGOSSYOOKMP-UHFFFAOYSA-N 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 125000004430 oxygen atom Chemical group O* 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 239000000725 suspension Substances 0.000 description 3
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 229910021578 Iron(III) chloride Inorganic materials 0.000 description 2
- 239000004372 Polyvinyl alcohol Substances 0.000 description 2
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 description 2
- 238000010306 acid treatment Methods 0.000 description 2
- 230000000844 anti-bacterial effect Effects 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000002708 enhancing effect Effects 0.000 description 2
- 230000001747 exhibiting effect Effects 0.000 description 2
- 125000005843 halogen group Chemical group 0.000 description 2
- 125000001183 hydrocarbyl group Chemical group 0.000 description 2
- 229920001477 hydrophilic polymer Polymers 0.000 description 2
- 239000005457 ice water Substances 0.000 description 2
- 238000005468 ion implantation Methods 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 238000013032 photocatalytic reaction Methods 0.000 description 2
- 229920002451 polyvinyl alcohol Polymers 0.000 description 2
- 229920000036 polyvinylpyrrolidone Polymers 0.000 description 2
- 239000001267 polyvinylpyrrolidone Substances 0.000 description 2
- 235000013855 polyvinylpyrrolidone Nutrition 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000000746 purification Methods 0.000 description 2
- 239000000376 reactant Substances 0.000 description 2
- 230000004043 responsiveness Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 239000011780 sodium chloride Substances 0.000 description 2
- 238000003980 solgel method Methods 0.000 description 2
- 238000003746 solid phase reaction Methods 0.000 description 2
- JMXKSZRRTHPKDL-UHFFFAOYSA-N titanium ethoxide Chemical compound [Ti+4].CC[O-].CC[O-].CC[O-].CC[O-] JMXKSZRRTHPKDL-UHFFFAOYSA-N 0.000 description 2
- YONPGGFAJWQGJC-UHFFFAOYSA-K titanium(iii) chloride Chemical compound Cl[Ti](Cl)Cl YONPGGFAJWQGJC-UHFFFAOYSA-K 0.000 description 2
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- PMVSDNDAUGGCCE-TYYBGVCCSA-L Ferrous fumarate Chemical compound [Fe+2].[O-]C(=O)\C=C\C([O-])=O PMVSDNDAUGGCCE-TYYBGVCCSA-L 0.000 description 1
- 241000233866 Fungi Species 0.000 description 1
- WHNWPMSKXPGLAX-UHFFFAOYSA-N N-Vinyl-2-pyrrolidone Chemical compound C=CN1CCCC1=O WHNWPMSKXPGLAX-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 229920003081 Povidone K 30 Polymers 0.000 description 1
- 238000000862 absorption spectrum Methods 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000004887 air purification Methods 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000003373 anti-fouling effect Effects 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 150000001735 carboxylic acids Chemical class 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000004440 column chromatography Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000004332 deodorization Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 239000012153 distilled water Substances 0.000 description 1
- 238000000635 electron micrograph Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 230000005281 excited state Effects 0.000 description 1
- 238000000605 extraction Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 229910052740 iodine Inorganic materials 0.000 description 1
- 239000011630 iodine Substances 0.000 description 1
- FBAFATDZDUQKNH-UHFFFAOYSA-M iron chloride Chemical compound [Cl-].[Fe] FBAFATDZDUQKNH-UHFFFAOYSA-M 0.000 description 1
- 150000002506 iron compounds Chemical class 0.000 description 1
- RUTXIHLAWFEWGM-UHFFFAOYSA-H iron(3+) sulfate Chemical compound [Fe+3].[Fe+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O RUTXIHLAWFEWGM-UHFFFAOYSA-H 0.000 description 1
- 229910000360 iron(III) sulfate Inorganic materials 0.000 description 1
- 125000001449 isopropyl group Chemical group [H]C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 230000004298 light response Effects 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 125000004108 n-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])([H])C([H])([H])* 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920002620 polyvinyl fluoride Polymers 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 125000001436 propyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])[H] 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000006479 redox reaction Methods 0.000 description 1
- 230000027756 respiratory electron transport chain Effects 0.000 description 1
- 125000002914 sec-butyl group Chemical group [H]C([H])([H])C([H])([H])C([H])(*)C([H])([H])[H] 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 125000000999 tert-butyl group Chemical group [H]C([H])([H])C(*)(C([H])([H])[H])C([H])([H])[H] 0.000 description 1
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 description 1
- MTAYDNKNMILFOK-UHFFFAOYSA-K titanium(3+);tribromide Chemical compound Br[Ti](Br)Br MTAYDNKNMILFOK-UHFFFAOYSA-K 0.000 description 1
Landscapes
- Catalysts (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
Description
本発明は、露出結晶面に遷移金属イオンが担持された酸化チタン粒子、その製造方法、及び該酸化チタン粒子からなる光触媒に関する。 The present invention relates to titanium oxide particles having transition metal ions supported on exposed crystal planes, a method for producing the same, and a photocatalyst comprising the titanium oxide particles.
従来、酸化チタン光触媒の性能向上に関する研究は、反応物質の吸着能力を向上させることにより光触媒能を向上させることができるという点に着目し、酸化チタンをいかに微粒子化するかに終始していたが、その技術も限界に直面していた。 In the past, research on improving the performance of titanium oxide photocatalysts has focused on the point that photocatalytic performance can be improved by improving the adsorption capacity of reactants, but how to make titanium oxide finer. The technology was also facing limitations.
酸化チタンはバンドギャップエネルギー以上のエネルギーを有する光を吸収すると価電子帯の電子が伝導帯に励起し、価電子帯にホール、伝導帯に励起電子が生成し、これらは酸化チタン粒子表面へ拡散する。酸化チタンの光触媒反応は、該励起電子が還元作用を、該ホールが強い酸化作用を有することを利用して、表面に吸着した物質を酸化、あるいは還元することによって進行する。酸化チタンの光触媒反応は、１つの光触媒粒子上で酸化反応と還元反応という正反対の反応が起こるため、励起電子とホールとの再結合や逆反応が容易に進行し、それにより反応効率が激減することが知られている。酸化反応と還元反応の反応場を空間的に分離することが、逆反応を抑制し、光触媒活性を高める上で重要であり、特定面が露出した酸化チタンは各結晶面の特性によって酸化反応と還元反応の反応場を分離することができ、効率よく反応が進行することが分かってきた。 When titanium oxide absorbs light with energy higher than the band gap energy, electrons in the valence band are excited in the conduction band, holes are generated in the valence band, and excited electrons are generated in the conduction band, which diffuse to the surface of the titanium oxide particles. To do. The photocatalytic reaction of titanium oxide proceeds by oxidizing or reducing the substance adsorbed on the surface by utilizing the reducing action of the excited electrons and the strong oxidizing action of the holes. In the photocatalytic reaction of titanium oxide, the opposite reactions of oxidation reaction and reduction reaction occur on one photocatalyst particle, so recombination and reverse reaction of excited electrons and holes proceed easily, thereby drastically reducing the reaction efficiency. It is known. Spatial separation of the reaction field between the oxidation reaction and the reduction reaction is important for suppressing the reverse reaction and enhancing the photocatalytic activity. Titanium oxide with a specific surface exposed is separated from the oxidation reaction depending on the characteristics of each crystal face. It has been found that the reaction field of the reduction reaction can be separated and the reaction proceeds efficiently.
そして、特許文献１には、酸化チタンにアルカリ性過酸化水素水処理、硫酸処理、又はフッ化水素酸処理を施して新規露出結晶面が発現した酸化チタン結晶を作る方法が記載されており、得られた新規露出結晶面が発現した酸化チタンからなる光触媒は高い酸化触媒性能を有することが記載されている。前記新規露出結晶面が発現した酸化チタンとしては、（１）ルチル型酸化チタンから得られる、新規に（１２１）面を発現させた酸化チタン結晶、（２）ルチル型酸化チタンから得られる、新規に（００１）（１２１）（０２１）（０１０）面を発現させた酸化チタン結晶、（３）ルチル型酸化チタンから得られる、新規に（０２１）面を発現させた酸化チタン結晶、（４）アナターゼ型酸化チタンから得られる、新規に（１２０）面を発現させた酸化チタン結晶、（５）アナターゼ型酸化チタンから得られる、新規に（１２２）面を発現させた酸化チタン結晶、（６）アナターゼ型酸化チタンから得られる、新規に（１１２）面を発現させた酸化チタン結晶が開示されている。 Patent Document 1 describes a method for producing a titanium oxide crystal in which a newly exposed crystal plane is expressed by subjecting titanium oxide to alkaline hydrogen peroxide treatment, sulfuric acid treatment, or hydrofluoric acid treatment. It is described that the photocatalyst made of titanium oxide in which the newly exposed crystal plane is expressed has high oxidation catalyst performance. Titanium oxide with the newly exposed crystal plane developed is (1) obtained from rutile type titanium oxide, titanium oxide crystal with newly developed (121) plane, and (2) new type obtained from rutile type titanium oxide. (4) a titanium oxide crystal having a (001) (121) (021) (010) plane developed thereon, (3) a titanium oxide crystal having a novel (021) plane obtained from a rutile-type titanium oxide, (6) a titanium oxide crystal newly obtained from anatase-type titanium oxide and (5) newly developed (122) face obtained from anatase-type titanium oxide; A novel (112) faced titanium oxide crystal obtained from anatase-type titanium oxide is disclosed.
しかしながら、酸化チタンは、紫外線の照射下では優れた光触媒能を発揮することができるが、太陽光や白熱灯、蛍光灯等の通常の生活空間における光源に含まれる紫外線量は４％程度と少なく、大部分が可視光線と赤外線で構成されていることから、このような光源下では十分な光触媒能を発揮することができないという問題があった。 However, titanium oxide can exhibit excellent photocatalytic activity under irradiation of ultraviolet rays, but the amount of ultraviolet rays contained in light sources in ordinary living spaces such as sunlight, incandescent lamps and fluorescent lamps is as low as about 4%. Since most of the light is composed of visible light and infrared light, there is a problem that sufficient photocatalytic activity cannot be exhibited under such a light source.
その解決方法としては、酸化チタンに窒素や特定の金属などをドーピングすることにより、ハンドギャップを小さくし、可視光応答性を付与する方法が挙げられる。金属をドーピングする方法としては、一般にゾルゲル法、固相反応法、イオン注入法などが知られているが、ゾルゲル法では、加水分解及び重合反応を均一に起こさせるため、反応系中のチタン濃度を１％以下の低濃度に制限することが一般的であり、生産効率が低いという問題や、分解生成物の除去に手間がかかる等の問題があった。また、固相反応法では反応を均一に起こさせるため、高温で長時間反応させることが必要であり、生産性に欠けるという問題があった。さらにまた、イオン注入法では大きなエネルギーで金属イオンを酸化チタン中に注入するため、大掛かりな設備が必要となってくることが問題であった。 As a solution to this problem, a method of reducing the hand gap and imparting visible light responsiveness by doping nitrogen oxide or a specific metal with titanium oxide can be mentioned. As a method for doping a metal, a sol-gel method, a solid-phase reaction method, an ion implantation method, etc. are generally known. However, in the sol-gel method, the concentration of titanium in the reaction system is uniform in order to cause hydrolysis and polymerization reaction uniformly. Is generally limited to a low concentration of 1% or less, and there are problems such as low production efficiency and troublesome removal of decomposition products. Further, in the solid phase reaction method, in order to cause the reaction to occur uniformly, it is necessary to carry out the reaction at a high temperature for a long time, and there is a problem that the productivity is lacking. Furthermore, in the ion implantation method, metal ions are implanted into titanium oxide with a large energy, which requires a large facility.
従って、本発明の目的は、紫外線域から可視光線域までの広い波長範囲に応答性を有し、太陽光や白熱灯、蛍光灯等の通常の生活空間における光源下でも高い触媒活性を発揮することができる酸化チタン粒子と、この酸化チタン粒子からなる光触媒、及び該酸化チタン粒子の製造方法を提供することにある。 Therefore, the object of the present invention is to respond to a wide wavelength range from the ultraviolet range to the visible light range, and to exhibit high catalytic activity even under a light source in a normal living space such as sunlight, incandescent lamp, fluorescent lamp, etc. An object of the present invention is to provide titanium oxide particles that can be produced, a photocatalyst comprising the titanium oxide particles, and a method for producing the titanium oxide particles.
本発明者等は、上記課題を解決するため鋭意検討した結果、露出結晶面の特定の面に遷移金属イオンを担持させた酸化チタン粒子は、紫外線域から可視光線域までの広い波長範囲に応答性を獲得することができ、その上、励起電子とホールとの分離性を極めて高いものとすることができ、励起電子とホールとの再結合や逆反応の進行を抑制することができるため、飛躍的に光触媒能を向上させることができることを見出した。 As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that titanium oxide particles carrying transition metal ions on a specific surface of the exposed crystal plane respond to a wide wavelength range from the ultraviolet region to the visible light region. In addition, the separation between the excited electrons and holes can be made extremely high, and the recombination between the excited electrons and holes and the progress of the reverse reaction can be suppressed. It has been found that the photocatalytic ability can be dramatically improved.
また、遷移金属イオンを担持する際に励起光を照射すると、大掛かりな設備などを要することなく容易に、且つ効率よく、特定面に選択的に遷移金属イオンを担持することができることを見出した。本発明はこれらの知見に基づいて完成させたものである。 Further, it has been found that when the excitation light is irradiated when supporting the transition metal ion, the transition metal ion can be selectively supported on a specific surface easily and efficiently without requiring a large facility. The present invention has been completed based on these findings.
すなわち、本発明は露出結晶面を有する酸化チタン粒子の露出結晶面のうち酸化反応面に、遷移金属イオンが面選択的に担持されていることを特徴とする金属イオン担持酸化チタン粒子を提供する。 That is, the present invention provides metal ion-carrying titanium oxide particles characterized in that transition metal ions are selectively supported on an oxidation reaction surface among exposed crystal surfaces of titanium oxide particles having an exposed crystal surface. .
露出結晶面を有する酸化チタン粒子としては、ルチル型酸化チタン粒子又はアナターゼ型酸化チタン粒子が好ましい。 As the titanium oxide particles having an exposed crystal face, rutile type titanium oxide particles or anatase type titanium oxide particles are preferable.
遷移金属イオンとしては、鉄イオンが好ましい。 As a transition metal ion, an iron ion is preferable.
遷移金属イオンは、露出結晶面のうち、（００１）面、（１１１）面及び（０１１）面から選択された少なくとも１つの面に選択的に担持されていることが好ましい。 The transition metal ions are preferably selectively supported on at least one surface selected from the ( 001) plane, the (111) plane, and the (011) plane among the exposed crystal planes.
本発明は、また、上記金属イオン担持酸化チタン粒子からなる光触媒を提供する。 The present invention also provides a photocatalyst comprising the metal ion-supported titanium oxide particles.
本発明は、さらにまた、励起光照射下、酸化チタン粒子に遷移金属イオンを担持させる工程を有する前記金属イオン担持酸化チタン粒子の製造方法を提供する。
尚、本明細書には上記発明の他に、露出結晶面を有する酸化チタン粒子に、遷移金属イオンが面選択的に担持されていることを特徴とする金属イオン担持酸化チタン粒子についても記載する。
The present invention further provides a method for producing the metal ion-carrying titanium oxide particles, comprising the step of carrying transition metal ions on the titanium oxide particles under excitation light irradiation.
In addition to the above-described invention, the present specification also describes metal ion-carrying titanium oxide particles characterized in that transition metal ions are selectively supported on titanium oxide particles having an exposed crystal plane. .
本発明に係る金属イオン担持酸化チタン粒子は、遷移金属イオンが担持されているため、紫外線域から可視光線域までの広い波長範囲の光を吸収することにより、価電子帯にホール、伝導帯に励起電子を生成し、表面の物質を酸化、或いは還元する反応を行うことができる。そのため、太陽光や白熱灯、蛍光灯等の通常の生活空間における光源を効率よく利用することができる。また、酸化チタン粒子が露出結晶面を有し、遷移金属イオンが該露出結晶面の特定の面に選択的に担持されているため、光吸収により生じた励起電子とホールの分離性を著しく向上させることができる。そのため、励起電子とホールの再結合及び逆反応の進行を抑制することができ、極めて高い光触活性を示すことができる。 Since the metal ion-carrying titanium oxide particles according to the present invention carry transition metal ions, they absorb light in a wide wavelength range from the ultraviolet region to the visible light region, so that the valence band has holes and the conduction band. A reaction for generating excited electrons and oxidizing or reducing a substance on the surface can be performed. Therefore, it is possible to efficiently use a light source in a normal living space such as sunlight, an incandescent lamp, and a fluorescent lamp. In addition, the titanium oxide particles have exposed crystal planes, and transition metal ions are selectively supported on specific surfaces of the exposed crystal planes, greatly improving the separation between excited electrons and holes generated by light absorption. Can be made. Therefore, recombination of excited electrons and holes and the progress of reverse reaction can be suppressed, and extremely high photocatalytic activity can be exhibited.
また、本発明に係る金属イオン担持酸化チタン粒子の製造方法によれば、遷移金属イオンを担持する工程において励起光照射を行うため、容易に酸化チタン粒子の露出結晶面のうち酸化反応面にのみに遷移金属イオンを吸着させることができ、高い生産性で効率よく本発明に係る金属イオン担持酸化チタン粒子を製造することができ、大掛かりな設備なども必要としない。そのため、本発明に係る金属イオン担持酸化チタン粒子の製造方法は工業化に適した方法である。 Also, according to the method for producing metal ion-carrying titanium oxide particles according to the present invention, excitation light irradiation is performed in the step of carrying transition metal ions, so that only the oxidation reaction surface of the exposed crystal surface of the titanium oxide particles can be easily obtained. Thus, transition metal ions can be adsorbed on the substrate, and the metal ion-carrying titanium oxide particles according to the present invention can be efficiently produced with high productivity, and no large-scale equipment is required. Therefore, the manufacturing method of the metal ion carrying | support titanium oxide particle which concerns on this invention is a method suitable for industrialization.
本発明に係る金属イオン担持酸化チタン粒子は、露出結晶面を有する酸化チタン粒子に、遷移金属イオンが面選択的に担持されていることを特徴とする。 The metal ion-carrying titanium oxide particles according to the present invention are characterized in that transition metal ions are supported in a surface selective manner on titanium oxide particles having an exposed crystal plane.
酸化チタン粒子としては、例えば、ルチル型、アナターゼ型、ブルッカイト型酸化チタン粒子等を挙げることができる。本発明においては、なかでも、安定な結晶面が露出している点でルチル型、又はアナターゼ型酸化チタン粒子が好ましい。 Examples of the titanium oxide particles include rutile type, anatase type, brookite type titanium oxide particles, and the like. In the present invention, rutile type or anatase type titanium oxide particles are particularly preferable in that a stable crystal face is exposed.
ルチル型酸化チタン粒子の主な露出結晶面としては、例えば、（１１０）（００１）（１１１）（０１１）面等を挙げることができる。本発明における露出結晶面を有するルチル型酸化チタン粒子としては、例えば、（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子、（１１０）（０１１）面を有するロッド状ルチル型酸化チタン粒子、（００１）（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子等や、これらのルチル型酸化チタン粒子に表面処理を施すことにより得られる、新たな露出面［例えば、（００１）面］を発現させたルチル型酸化チタン粒子などを挙げることができる。本発明においては、なかでも、酸化反応と還元反応の反応場を空間的により大きく引き離すことができ、励起電子とホールとの再結合及び逆反応の進行を抑制することができる点で、（００１）（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子［（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子に表面処理を施すことにより得られる、新たな露出面（００１）を発現させたルチル型酸化チタン粒子を含む］が好ましい。 Examples of main exposed crystal planes of rutile-type titanium oxide particles include (110) (001) (111) (011) planes. Examples of the rutile-type titanium oxide particles having an exposed crystal face in the present invention include rod-like rutile-type titanium oxide particles having a (110) (111) face and rod-like rutile-type titanium oxide having a (110) (011) face. Particles, rod-shaped rutile-type titanium oxide particles having (001) (110) (111) faces, etc., and new exposed surfaces obtained by subjecting these rutile-type titanium oxide particles to surface treatment [for example, (001 ) Surface], and the like. In the present invention, in particular, the reaction fields of the oxidation reaction and the reduction reaction can be separated more spatially, and the recombination of excited electrons and holes and the progress of the reverse reaction can be suppressed (001). ) Rod-shaped rutile titanium oxide particles having (110) (111) surface [New exposed surface (001 obtained by subjecting rod-shaped rutile titanium oxide particles having (110) (111) surface to surface treatment) It contains rutile-type titanium oxide particles that express)].
アナターゼ型酸化チタン粒子の主な露出結晶面としては、例えば、（００１）（１０１）面等を挙げることができる。本発明における露出結晶面を有するアナターゼ型酸化チタン粒子としては、（００１）（１０１）面を有するアナターゼ型酸化チタン粒子や、前記アナターゼ型酸化チタン粒子に表面処理を行うことにより得られる（００１）（１０１）面を有し、十面体構造を呈するアナターゼ型酸化チタン粒子等を挙げることができる。 Examples of the main exposed crystal plane of the anatase-type titanium oxide particles include (001) (101) plane. The anatase-type titanium oxide particles having an exposed crystal face in the present invention can be obtained by subjecting anatase-type titanium oxide particles having a (001) (101) face or surface treatment to the anatase-type titanium oxide particles (001). Anatase-type titanium oxide particles having a (101) plane and exhibiting a decahedral structure can be mentioned.
酸化チタン粒子として、例えば、（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子は、チタン化合物を水性媒体（例えば、水又は水と水溶性有機溶媒との混合液）中で水熱処理［例えば、１００〜２００℃、３〜４８時間（好ましくは６〜１２時間）］することにより合成することができる。また、水熱処理の際にハロゲン化物を添加すると、得られる粒子のサイズ及び表面積を調整することができるため好ましい。 As the titanium oxide particles, for example, rod-shaped rutile type titanium oxide particles having (110) (111) faces are obtained by hydrothermal treatment of a titanium compound in an aqueous medium (for example, water or a mixture of water and a water-soluble organic solvent). [E.g., 100 to 200 ° C., 3 to 48 hours (preferably 6 to 12 hours)]. Moreover, it is preferable to add a halide during the hydrothermal treatment because the size and surface area of the obtained particles can be adjusted.
前記チタン化合物としては、３価のチタン化合物、４価のチタン化合物を挙げることができる。３価のチタン化合物としては、例えば、三塩化チタンや三臭化チタンなどのトリハロゲン化チタン等を挙げることができる。本発明における３価のチタン化合物としては、なかでも安価で、入手が容易な点で三塩化チタン（ＴｉＣｌ3）が好ましい。 Examples of the titanium compound include a trivalent titanium compound and a tetravalent titanium compound. Examples of the trivalent titanium compound include titanium trihalides such as titanium trichloride and titanium tribromide. As the trivalent titanium compound in the present invention, titanium trichloride (TiCl 3 ) is preferable because it is inexpensive and easily available.
また、本発明における４価のチタン化合物は、例えば、下記式（１）で表される化合物等を挙げることができる。
Ｔｉ（ＯＲ）tＸ4-t （１）
（式中、Ｒは炭化水素基を示し、Ｘはハロゲン原子を示す。ｔは０〜３の整数を示す）
Moreover, the tetravalent titanium compound in this invention can mention the compound etc. which are represented by following formula (1), for example.
Ti (OR) t X 4-t (1)
(In the formula, R represents a hydrocarbon group, X represents a halogen atom, and t represents an integer of 0 to 3).
Ｒにおける炭化水素基としては、例えば、メチル、エチル、プロピル、イソプロピル、ｎ−ブチル、sec−ブチル、tert−ブチル等のＣ1-4脂肪族炭化水素基等を挙げることができる。 Examples of the hydrocarbon group for R include C 1-4 aliphatic hydrocarbon groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl and tert-butyl.
Ｘにおけるハロゲン原子としては、塩素、臭素、ヨウ素等を挙げることができる。 Examples of the halogen atom for X include chlorine, bromine, iodine and the like.
このような４価のチタン化合物としては、例えば、ＴｉＣｌ4、ＴｉＢｒ4、ＴｉＩ4などのテトラハロゲン化チタン；Ｔｉ（ＯＣＨ3）Ｃｌ3、Ｔｉ（ＯＣ2Ｈ5）Ｃｌ3、Ｔｉ（ＯＣ4Ｈ9）Ｃｌ3、Ｔｉ（ＯＣ2Ｈ5）Ｂｒ3、Ｔｉ（ＯＣ4Ｈ9）Ｂｒ3などのトリハロゲン化アルコキシチタン；Ｔｉ（ＯＣＨ3）2Ｃｌ2、Ｔｉ（ＯＣ2Ｈ5）2Ｃｌ2、Ｔｉ（ＯＣ4Ｈ9）2Ｃｌ2、Ｔｉ（ＯＣ2Ｈ5）2Ｂｒ2などのジハロゲン化ジアルコキシチタン；Ｔｉ（ＯＣＨ3）3Ｃｌ、Ｔｉ（ＯＣ2Ｈ5）3Ｃｌ、Ｔｉ（ＯＣ4Ｈ9）3Ｃｌ、Ｔｉ（ＯＣ2Ｈ5）3Ｂｒなどのモノハロゲン化トリアルコキシチタン等を挙げることができる。本発明における４価のチタン化合物としては、なかでも安価で、入手が容易な点で、テトラハロゲン化チタンが好ましく、特に四塩化チタン（ＴｉＣｌ4）が好ましい。 Examples of such tetravalent titanium compounds include titanium tetrahalides such as TiCl 4 , TiBr 4 , and TiI 4 ; Ti (OCH 3 ) Cl 3 , Ti (OC 2 H 5 ) Cl 3 , and Ti (OC 4). Trihalogenated alkoxytitanium such as H 9 ) Cl 3 , Ti (OC 2 H 5 ) Br 3 , Ti (OC 4 H 9 ) Br 3 ; Ti (OCH 3 ) 2 Cl 2 , Ti (OC 2 H 5 ) 2 Dihalogenated dialkoxytitanium such as Cl 2 , Ti (OC 4 H 9 ) 2 Cl 2 , Ti (OC 2 H 5 ) 2 Br 2 ; Ti (OCH 3 ) 3 Cl, Ti (OC 2 H 5 ) 3 Cl, Examples thereof include monohalogenated trialkoxytitanium such as Ti (OC 4 H 9 ) 3 Cl and Ti (OC 2 H 5 ) 3 Br. As the tetravalent titanium compound in the present invention, titanium tetrahalide is preferable, and titanium tetrachloride (TiCl 4 ) is particularly preferable because it is inexpensive and easily available.
また、新たな露出面（００１）を発現させたロッド状ルチル型酸化チタン粒子や、十面体構造を有し（００１）（１０１）面を有するアナターゼ型酸化チタンは、前記チタン化合物を、構造制御剤として親水性ポリマー（例えば、ポリビニルピロリドン、ポリビニルアルコール）の存在下、水性媒体中で水熱処理［例えば、１００〜２００℃、３〜４８時間（好ましくは６〜１２時間）］して［００１］方向へ成長させることにより合成することができる。 In addition, rod-shaped rutile-type titanium oxide particles having a newly exposed surface (001) and anatase-type titanium oxide having a decahedral structure (001) (101) surface control the structure of the titanium compound. Hydrothermal treatment [for example, 100 to 200 ° C., 3 to 48 hours (preferably 6 to 12 hours)] in an aqueous medium in the presence of a hydrophilic polymer (for example, polyvinylpyrrolidone or polyvinyl alcohol) as an agent [001] It can be synthesized by growing in the direction.
また、特に、前記チタン化合物として４価のチタン化合物を使用する場合は、構造制御剤として親水性ポリマーを添加しなくとも、反応温度１１０〜２２０℃（好ましくは１５０℃〜２２０℃）、その反応温度における飽和蒸気圧以上の圧力下、水性媒体中で２時間以上（好ましくは５〜１５時間）水熱処理を施すことにより（００１）（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子を合成することができる。 In particular, when a tetravalent titanium compound is used as the titanium compound, the reaction temperature is 110 to 220 ° C. (preferably 150 ° C. to 220 ° C.) without adding a hydrophilic polymer as a structure control agent. Rod-shaped rutile titanium oxide particles having (001) (110) (111) faces by hydrothermal treatment in an aqueous medium for 2 hours or more (preferably 5 to 15 hours) under a pressure equal to or higher than the saturated vapor pressure at temperature Can be synthesized.
その他、新たな露出面（００１）を発現させたルチル型酸化チタン粒子は、ルチル型酸化チタン粒子を硫酸（好ましくは、５０重量％以上の高濃度の硫酸、特に好ましくは濃硫酸）中に投入し、加熱下で撹拌することにより、酸化チタン粒子の稜又は頂点の部位を浸食（溶解）して合成することもできる。 In addition, for the rutile type titanium oxide particles that have developed a new exposed surface (001), the rutile type titanium oxide particles are put into sulfuric acid (preferably high concentration sulfuric acid of 50% by weight or more, particularly preferably concentrated sulfuric acid). And it can also synthesize | combine by eroding (dissolving) the site | part of the edge or vertex of a titanium oxide particle by stirring under heating.
本発明に係る金属イオン担持酸化チタン粒子は、酸化チタン粒子の露出結晶面における酸化反応面又は還元反応面のうち一方の面に選択的に遷移金属イオンが担持されていることが、励起電子とホールの分離性を高める上で好ましく、特に、酸化反応面に選択的に遷移金属イオンが担持されていることが好ましい。 The metal ion-carrying titanium oxide particles according to the present invention are such that the transition metal ions are selectively carried on one of the oxidation reaction surface or the reduction reaction surface in the exposed crystal plane of the titanium oxide particles. It is preferable from the viewpoint of enhancing hole separation, and it is particularly preferable that transition metal ions are selectively supported on the oxidation reaction surface.
ルチル型酸化チタンの酸化反応面としては、例えば、（１１０）（１１１）面を有するロッド状ルチル型酸化チタンの場合は（１１１）面、（１１０）（０１１）面を有するロッド状ルチル型酸化チタン粒子の場合は（０１１）面が挙げられる。また、（００１）（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子［前記の（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子に表面処理を施すことにより得られる、新たな露出面（００１）を発現させたルチル型酸化チタン粒子を含む］の場合は、（１１１）面と（００１）面が酸化反応面として挙げられる。 As an oxidation reaction surface of rutile type titanium oxide, for example, in the case of rod type rutile type titanium oxide having (110) (111) plane, rod type rutile type oxidation having (111) plane and (110) (011) plane. In the case of titanium particles, the (011) plane is mentioned. Further, rod-shaped rutile type titanium oxide particles having (001) (110) (111) surface [obtained by subjecting the rod-shaped rutile type titanium oxide particles having (110) (111) surface to surface treatment, In the case of [including rutile-type titanium oxide particles in which a new exposed surface (001) is expressed], the (111) surface and the (001) surface are exemplified as the oxidation reaction surface.
アナターゼ型酸化チタンの酸化反応面としては、例えば、（００１）（１０１）面を有するアナターゼ型酸化チタンの場合は（００１）面、（００１）（１０１）面を有し、十面体構造を呈するアナターゼ型酸化チタン粒子の場合は（００１）面が挙げられる。 As an oxidation reaction surface of anatase-type titanium oxide, for example, in the case of anatase-type titanium oxide having (001) (101) plane, it has (001) plane and (001) (101) plane and exhibits a decahedral structure. In the case of anatase-type titanium oxide particles, the (001) plane may be mentioned.
本発明においては、なかでも、（００１）（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子［（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子に表面処理を施すことにより得られる、新たな露出面（００１）を発現させたロッド状ルチル型酸化チタン粒子を含む］の（００１）（１１１）面、（００１）（１０１）面を有するアナターゼ型酸化チタン粒子の（００１）面に遷移金属イオンが選択的に担持されていることが、酸化反応面と還元反応面の反応場を空間的により大きく引き離すことができ、それにより励起電子とホールの再結合及び逆反応の進行を極めて低いレベルにまで抑制することができ、より高い光触媒活性を発揮することができる点で好ましい。 In the present invention, the rod-shaped rutile-type titanium oxide particles having (001) (110) (111) planes [the rod-shaped rutile-type titanium oxide particles having (110) (111) planes are subjected to a surface treatment). Anodase-type titanium oxide particles having (001) (111) face and (001) (101) face of (including rod-shaped rutile-type titanium oxide particles expressing a new exposed face (001) obtained by Since the transition metal ions are selectively supported on the (001) plane, the reaction fields of the oxidation reaction surface and the reduction reaction surface can be separated more spatially, thereby causing recombination and reverse reaction of excited electrons and holes. Is preferable in that it can be suppressed to a very low level and can exhibit higher photocatalytic activity.
また、本発明における酸化チタン粒子の比表面積としては、例えば、２０〜８０ｍ2／ｇ、好ましくは、２０〜６０ｍ2／ｇである。酸化チタン粒子の比表面積が上記範囲を下回ると、反応物質の吸着能力が低下して光触媒能が低下する傾向があり、一方、酸化チタン粒子の比表面積が上記範囲を上回ると、励起電子とホールの分離性が低下し、光触媒能が低下する傾向がある。 Moreover, as a specific surface area of the titanium oxide particle in this invention, it is 20-80 m < 2 > / g, for example, Preferably, it is 20-60 m < 2 > / g. When the specific surface area of the titanium oxide particles is below the above range, the adsorption capacity of the reactants tends to be reduced and the photocatalytic performance tends to be reduced. On the other hand, when the specific surface area of the titanium oxide particles exceeds the above range, excited electrons and holes There is a tendency that the separability of the photocatalyst decreases and the photocatalytic ability decreases.
遷移金属イオンの酸化チタン粒子への担持は、酸化チタン粒子に遷移金属イオンを含浸する含浸法により行うことができる。 The transition metal ions can be supported on the titanium oxide particles by an impregnation method in which the titanium oxide particles are impregnated with the transition metal ions.
遷移金属イオンとしては、可視光領域に吸収スペクトルを有し、励起状態で伝導帯に電子を注入することができるものであればよく、例えば、周期表第３〜第１１族元素イオン、なかでも周期表第８〜第１１族元素イオンが好ましく、特に、三価の鉄イオン（Ｆｅ3+）が好ましい。鉄イオンの酸化チタン粒子への担持においては、三価の鉄イオン（Ｆｅ3+）は吸着しやすく、二価の鉄イオン（Ｆｅ2+）は吸着しにくい特性を有するため、その特性を利用することにより容易に面選択性を付与することができるからである。 Any transition metal ion may be used as long as it has an absorption spectrum in the visible light region and can inject electrons into the conduction band in an excited state, such as Group 3 to 11 element ions in the periodic table. Periodic table group 8 to group 11 element ions are preferred, and trivalent iron ions (Fe 3+ ) are particularly preferred. When iron ions are supported on titanium oxide particles, trivalent iron ions (Fe 3+ ) are easily adsorbed, and divalent iron ions (Fe 2+ ) are difficult to adsorb. This is because surface selectivity can be easily imparted.
含浸は、具体的には、酸化チタン粒子を水溶液中に分散して浸漬し、撹拌しながら、遷移金属イオンを添加することにより行うことができ、例えば、遷移金属イオンとして三価の鉄イオン（Ｆｅ3+）を使用する場合は、鉄化合物（例えば、硝酸鉄（III）、硫酸鉄（III）、塩化鉄（III）等）を添加することにより行うことができる。 Specifically, the impregnation can be performed by dispersing and immersing the titanium oxide particles in an aqueous solution and adding a transition metal ion while stirring. For example, trivalent iron ions ( When Fe 3+ is used, it can be carried out by adding an iron compound (for example, iron (III) nitrate, iron (III) sulfate, iron (III) chloride, etc.).
遷移金属イオンの添加量としては、例えば、酸化チタン粒子に対して０．０１〜３．０重量％程度、好ましくは０．０５〜１．０重量％程度である。遷移金属イオンの添加量が上記範囲を下回ると、酸化チタン粒子表面における遷移金属イオンの被覆率が低下し、光触媒活性が低下する傾向があり、一方、遷移金属イオンの添加量が上記範囲を上回ると、注入電子の逆電子移動等により励起電子が有効に作用せず、光触媒活性が低下する傾向がある。浸漬時間としては、例えば、３０分から２４時間程度、好ましくは１〜１０時間程度である。 The addition amount of the transition metal ion is, for example, about 0.01 to 3.0% by weight, preferably about 0.05 to 1.0% by weight with respect to the titanium oxide particles. When the addition amount of transition metal ions is below the above range, the coverage of transition metal ions on the surface of the titanium oxide particles tends to decrease, and the photocatalytic activity tends to decrease, while the addition amount of transition metal ions exceeds the above range. Then, the excited electrons do not act effectively due to the reverse electron transfer of the injected electrons, and the photocatalytic activity tends to decrease. The immersion time is, for example, about 30 minutes to 24 hours, preferably about 1 to 10 hours.
そして、本発明においては、酸化チタン粒子に遷移金属イオンを含浸する際に励起光を照射する工程を含むことを特徴とする。励起光を照射すると、酸化チタン粒子の価電子帯の電子が伝導帯に励起し、価電子帯にホール、伝導帯に励起電子が生成し、これらは粒子表面へ拡散し、各露出結晶面の特性に従って励起電子とホールとが分離されて酸化反応面と還元反応面とを形成する。この状態で遷移金属イオンとして、例えば三価の鉄イオンの含浸を行うと、三価の鉄イオン（Ｆｅ3+）は酸化反応面には吸着するが、還元反応面では三価の鉄イオン（Ｆｅ3+）は二価の鉄イオン（Ｆｅ2+）に還元され、二価の鉄イオン（Ｆｅ2+）は吸着しにくい特性を有するため、溶液中に溶出し、結果として酸化反応面にのみ鉄イオン（Ｆｅ3+）が担持された金属イオン担持酸化チタン粒子を得ることができる。 And in this invention, when impregnating a transition metal ion to a titanium oxide particle, the process of irradiating excitation light is included, It is characterized by the above-mentioned. When irradiated with excitation light, the electrons in the valence band of the titanium oxide particles are excited in the conduction band, holes are generated in the valence band, and excited electrons are generated in the conduction band, which are diffused to the particle surface. Excited electrons and holes are separated according to the characteristics to form an oxidation reaction surface and a reduction reaction surface. In this state, for example, when trivalent iron ions are impregnated as transition metal ions, trivalent iron ions (Fe 3+ ) are adsorbed on the oxidation reaction surface, but trivalent iron ions ( Fe 3+ ) is reduced to divalent iron ions (Fe 2+ ), and divalent iron ions (Fe 2+ ) are difficult to adsorb, so they elute into the solution, resulting in an oxidation reaction surface. Only metal ion-carrying titanium oxide particles carrying iron ions (Fe 3+ ) can be obtained.
励起光の照射方法としては、バンドギャップエネルギー以上のエネルギーを有する光を照射することができればよく、例えば、紫外線を照射することにより行うことができる。紫外線照射手段としては、例えば、中・高圧水銀灯、ＵＶレーザー、ＵＶ−ＬＥＤ、ブラックライト等の紫外線を効率よく生成する光源を使用した紫外線露光装置等を使用することができる。励起光の照射量としては、例えば、０．１〜３００ｍＷ／ｃｍ2程度、好ましくは１〜５ｍＷ／ｃｍ2程度である。 As a method for irradiating the excitation light, it is only necessary to irradiate light having energy equal to or higher than the band gap energy. As the ultraviolet irradiation means, for example, an ultraviolet exposure apparatus using a light source that efficiently generates ultraviolet rays such as a medium / high pressure mercury lamp, a UV laser, a UV-LED, and a black light can be used. The irradiation amount of the excitation light is, for example, about 0.1 to 300 mW / cm 2 , preferably about 1 to 5 mW / cm 2 .
さらに、本発明においては、含浸の際に犠牲剤を添加することが好ましい。犠牲剤を添加することにより、酸化チタン粒子表面において、特定の露出結晶面に高い選択率で遷移金属イオンを担持させることができる。犠牲剤としては、それ自体が電子を放出しやすい有機化合物を使用することが好ましく、例えば、メタノール、エタノール等のアルコール；酢酸等のカルボン酸；エチレンジアミン四酢酸（ＥＤＴＡ）、トリエタノールアミン（ＴＥＡ）等のアミン等を挙げることができる。 Furthermore, in the present invention, it is preferable to add a sacrificial agent during the impregnation. By adding the sacrificial agent, transition metal ions can be supported on the exposed surface of the titanium oxide particles with high selectivity on the surface of the titanium oxide particles. As the sacrificial agent, it is preferable to use an organic compound that easily emits electrons. For example, alcohols such as methanol and ethanol; carboxylic acids such as acetic acid; ethylenediaminetetraacetic acid (EDTA) and triethanolamine (TEA) And the like.
犠牲剤の添加量としては、酸化チタン溶液の体積に応じて適宜調整することができ、例えば、酸化チタン溶液１００ｍＬに対して０．５〜５．０vol％程度、好ましくは１．０〜２．０vol％程度である。犠牲剤は過剰量を使用してもよい。 The addition amount of the sacrificial agent can be appropriately adjusted according to the volume of the titanium oxide solution, and is, for example, about 0.5 to 5.0 vol%, preferably 1.0 to 2% with respect to 100 mL of the titanium oxide solution. It is about 0 vol%. An excessive amount of the sacrificial agent may be used.
上記方法により得られた金属イオン担持酸化チタン粒子は、例えば、濾過、濃縮、蒸留、抽出、晶析、再結晶、カラムクロマトグラフィーなどの分離手段や、これらを組み合わせた分離手段により分離精製できる。 The metal ion-carrying titanium oxide particles obtained by the above method can be separated and purified by separation means such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, etc., or a separation means combining these.
本発明において、「遷移金属イオンが面選択的に担持」とは、露出結晶面を有する酸化チタン粒子に担持する遷移金属イオンの５０％を超える量（好ましくは７０％以上、特に好ましくは８０％以上）が２以上の露出結晶面のうち、全ての面ではなく、特定の面（例えば、特定の１面又は２面等）に担持されていることをいう。尚、面選択率の上限は１００％である。面選択率が低いと、酸化反応と還元反応の反応場の分離性が低下する傾向があり、励起電子とホールの再結合及び逆反応の進行を抑制することが困難となり、光触媒活性が低下する傾向がある。本発明において、面選択性は、透過型電子顕微鏡（ＴＥＭ）やエネルギー分散型蛍光Ｘ線分析装置（ＥＤＸ）を使用し、遷移金属イオン由来のシグナルを確認することで、各露出結晶面上の遷移金属イオンの有無により判定できる。また、面選択率は、例えば、金属イオン担持酸化チタン粒子の電子顕微鏡写真（例えば、ＳＥＭ等の写真）から、各結晶面における金属イオン担持部位の面積を求め、金属イオン担持部位の総面積に対する当該結晶面（例えば、酸化反応面或いは還元反応面）における金属イオン担持部位の面積の割合（％）として求めることができる。 In the present invention, “transition metal ions are selectively supported by the surface” means an amount exceeding 50% of transition metal ions supported on titanium oxide particles having an exposed crystal plane (preferably 70% or more, particularly preferably 80%). The above refers to being supported on a specific surface (for example, one specific surface or two surfaces) instead of all of the two or more exposed crystal surfaces. Note that the upper limit of the surface selectivity is 100%. If the surface selectivity is low, the separability of the reaction field between the oxidation reaction and the reduction reaction tends to decrease, and it becomes difficult to suppress the recombination of excited electrons and holes and the progress of the reverse reaction, resulting in a decrease in photocatalytic activity. Tend. In the present invention, the surface selectivity is determined on each exposed crystal plane by confirming a signal derived from a transition metal ion using a transmission electron microscope (TEM) or an energy dispersive X-ray fluorescence spectrometer (EDX). This can be determined by the presence or absence of transition metal ions. The surface selectivity is obtained, for example, from the electron micrograph (for example, a photograph of SEM or the like) of the metal ion-carrying titanium oxide particles, by determining the area of the metal ion-carrying site in each crystal plane, It can be determined as the ratio (%) of the area of the metal ion-supporting site on the crystal plane (for example, the oxidation reaction surface or the reduction reaction surface).
また、遷移金属イオンの担持量は、酸化チタン粒子表面の遷移金属イオン被覆率で表すことができ、例えば、被覆率が０．１〜２０．０％となる量が好ましく、なかでも、被覆率が０．１〜１０．０％（好ましくは、１．５〜５．０％）となる量が好ましい。被覆率が上記範囲を上回ると、励起電子が有効に作用せず、光触媒能が低下する傾向があり、一方、被覆率が上記範囲を下回ると、可視光線応答性が低下して光触媒能が低下する傾向がある。 The amount of transition metal ions supported can be represented by the transition metal ion coverage on the surface of the titanium oxide particles. For example, the coverage is preferably in an amount of 0.1 to 20.0%. Is preferably 0.1 to 10.0% (preferably 1.5 to 5.0%). If the coverage exceeds the above range, the excited electrons do not act effectively and the photocatalytic activity tends to decrease. On the other hand, if the coverage is below the above range, the visible light response decreases and the photocatalytic activity decreases. Tend to.
本発明において被覆率とは、金属イオン担持酸化チタン粒子の表面における吸着遷移金属イオンの占める割合をいい、例えば、遷移金属イオンとして鉄イオン（Ｆｅ3+）を使用する場合、ＩＣＰ発光分析により吸着率が１００％となる鉄イオン濃度をＸモルとし、鉄イオンが八面体型六配位錯体の結晶構造で酸化チタンに吸着し、さらに、酸化チタンの酸素原子と鉄原子とが結合して、酸素原子が四角錐の頂点となり鉄イオンがその中心に配位する形状で吸着が起こると仮定すると、鉄粒子１つの占有面積は、一辺が（１．９１×√２Å）の正方形と見なすことができる（図２参照）。尚、Ｆｅ3+−Ｏの原子間距離は、１．９１Åとした。ＢＥＴ比表面積（Ｙｍ2／ｇ）の酸化チタン粒子（Ｚｇ）の被覆率は、下記式により求めることができる。
被覆率（％）＝｛（１．９１×√２×１０-10）2×Ｘ×６．０２×１０23／Ｙ×Ｚ｝×１００
In the present invention, the coverage refers to the proportion of the adsorbed transition metal ions on the surface of the metal oxide-supported titanium oxide particles. For example, when iron ions (Fe 3+ ) are used as the transition metal ions, they are adsorbed by ICP emission analysis. The iron ion concentration at which the rate is 100% is X mol, the iron ions are adsorbed on titanium oxide in the crystal structure of the octahedral hexacoordination complex, and the oxygen atoms and iron atoms of titanium oxide are bonded, Assuming that adsorption occurs in a shape in which oxygen atoms are apexes of a quadrangular pyramid and iron ions are coordinated to the center, the occupied area of one iron particle can be regarded as a square with one side of (1.91 × √2Å). Yes (see FIG. 2). The interatomic distance of Fe 3+ —O was 1.91 mm. The coverage of the titanium oxide particles (Zg) having a BET specific surface area (Ym 2 / g) can be obtained by the following formula.
Coverage (%) = {(1.91 × √2 × 10 −10 ) 2 × X × 6.02 × 10 23 / Y × Z} × 100
本発明に係る金属イオン担持酸化チタン粒子においては、特に、遷移金属イオンが面選択的に担持され、且つ、その担持量が上記範囲内であることが、酸化反応と還元反応の反応場の分離性をより高めることができ、励起電子とホールとの再結合を抑制することができ、且つ、逆反応の進行をより一層抑制することができ、それにより高い光触媒活性を発揮することができる点で好ましい。 In the metal ion-supported titanium oxide particles according to the present invention, in particular, transition metal ions are supported in a surface-selective manner, and the supported amount is within the above range, so that the reaction fields of the oxidation reaction and the reduction reaction are separated. It is possible to further improve the property, to suppress the recombination between excited electrons and holes, and to further suppress the progress of the reverse reaction, thereby exhibiting a high photocatalytic activity. Is preferable.
本発明に係る金属イオン担持酸化チタン粒子は、紫外線域から可視光線域までの広い波長範囲に応答性を有し、太陽光や白熱灯、蛍光灯等の通常の生活空間における光を吸収して、高い触媒活性を発揮することができる。 The metal ion-supported titanium oxide particles according to the present invention are responsive to a wide wavelength range from the ultraviolet region to the visible light region, and absorb light in ordinary living spaces such as sunlight, incandescent lamps, and fluorescent lamps. High catalytic activity can be exhibited.
本発明に係る光触媒は、前記金属イオン担持酸化チタン粒子からなり、光の照射によって有害化学物質を水や二酸化炭素にまで分解することが可能であるため、抗菌防かび、脱臭、大気浄化、水質浄化、防汚などさまざまに応用することができる。また、従来の酸化チタン光触媒は紫外線が必要なため、紫外線の少ない室内では機能が充分に発揮できず、室内用途への応用はなかなか進まなかったが、本発明に係る光触媒は、紫外線域から可視光線域までの広い波長範囲に応答性を有し、太陽光や白熱灯、蛍光灯等の通常の生活空間における光を吸収して、高い触媒活性を発揮することができるため、室内などの低照度環境でも高いガス分解性能や抗菌作用を示し、室内の壁紙や家具をはじめ家庭内や病院、学校などの公共施設内での環境浄化、家電製品の高機能化など、広範囲への応用が可能である。 The photocatalyst according to the present invention is composed of the above-described metal ion-supported titanium oxide particles, and can decompose harmful chemical substances into water and carbon dioxide by light irradiation. Therefore, antibacterial fungi, deodorization, air purification, water quality Various applications such as purification and antifouling can be applied. In addition, since the conventional titanium oxide photocatalyst requires ultraviolet rays, its function cannot be sufficiently exhibited in a room with little ultraviolet rays, and its application to indoor applications has not progressed easily. However, the photocatalyst according to the present invention is visible from the ultraviolet region. Responsive to a wide wavelength range up to the light range, and absorbs light in normal living spaces such as sunlight, incandescent lamps, fluorescent lamps, etc., and exhibits high catalytic activity, so it can It exhibits high gas decomposition performance and antibacterial action even in illuminance environments, and can be applied to a wide range of applications such as indoor wallpaper, furniture, environmental purification in homes, hospitals, schools, and other public facilities, and advanced functionality of home appliances. It is.
以下、実施例により本発明をより具体的に説明するが、本発明はこれらの実施例により限定されるものではない。 EXAMPLES Hereinafter, although an Example demonstrates this invention more concretely, this invention is not limited by these Examples.
調製例１
テフロン（登録商標）塗装されたオートクレーブに、ＴｉＣｌ3水溶液（約２０％希塩酸溶液）を用い、５ＭのＮａＣｌ水溶液下において、水熱処理（２００℃、３時間）を施した。得られた反応物を遠心分離し、脱イオン水でリンスし、真空乾燥機（バキュームオーブン）で乾燥して、酸化チタン粒子を得た。得られた酸化チタン粒子を透過型電子顕微鏡（ＴＥＭ）で確認したところ、（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子（比表面積：３３ｍ2／ｇ）であった（図３）。
Preparation Example 1
An autoclave coated with Teflon (registered trademark) was subjected to hydrothermal treatment (200 ° C., 3 hours) using a TiCl 3 aqueous solution (approximately 20% dilute hydrochloric acid solution) in a 5 M NaCl aqueous solution. The obtained reaction product was centrifuged, rinsed with deionized water, and dried with a vacuum dryer (vacuum oven) to obtain titanium oxide particles. When the obtained titanium oxide particles were confirmed by a transmission electron microscope (TEM), they were rod-shaped rutile titanium oxide particles (specific surface area: 33 m 2 / g) having (110) (111) planes (FIG. 3). ).
得られた（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子（０．０５ｇ）を２−プロパノール（０．５２Ｍ）とＨ2ＰｔＣｌ6・６Ｈ2Ｏ（１ｍＭ）に加え懸濁液とした。得られた懸濁液から窒素ガスを完全に除去し、その後、５００Ｗの超高圧水銀ランプ用光源装置（商品名「ＳＸ−ＵＩ５０１ＨＱ」、ウシオ電機(株)製）を使用して紫外線を２４時間照射した（１ｍＷ／ｃｍ2）。紫外線照射により酸化チタン粒子粉末の色は白から灰色に変化した。このことから、Ｐｔが光析出したことがわかる。その後、懸濁液を遠心分離し、蒸留水で洗浄し、減圧下、７０℃で３時間乾燥してＰｔ担持酸化チタン粒子を得た。 The obtained rod-shaped rutile-type titanium oxide particles (0.05 g) having (110) (111) faces were added to 2-propanol (0.52 M) and H 2 PtCl 6 .6H 2 O (1 mM) to form a suspension. It was. Nitrogen gas is completely removed from the resulting suspension, and then UV light is applied for 24 hours using a 500 W ultra high pressure mercury lamp light source device (trade name “SX-UI501HQ”, manufactured by USHIO INC.). Irradiation (1 mW / cm 2 ). The color of the titanium oxide particle powder changed from white to gray by ultraviolet irradiation. This shows that Pt was photodeposited. Thereafter, the suspension was centrifuged, washed with distilled water, and dried under reduced pressure at 70 ° C. for 3 hours to obtain Pt-supported titanium oxide particles.
得られたＰｔ担持酸化チタン粒子を含む水溶液（２ｇ／Ｌ）にＰｂ（ＮＯ3）2（０．１Ｍ）を加え、硝酸を加えてｐＨを１．０に調整し、５００Ｗの水銀ランプを使用して紫外線を２４時間照射（０．１Ｗ／ｃｍ2）して、Ｐｔ・ＰｂＯ2担持酸化チタン粒子を得た。尚、紫外線照射により粉末の色は灰色から茶色に変化した。このことから、Ｐｂ2+イオンがＰｔ担持酸化チタン粒子により酸化されてＰｂＯ2となり析出したことがわかる。 Pb (NO 3 ) 2 (0.1M) is added to the aqueous solution (2 g / L) containing the obtained Pt-supported titanium oxide particles, the pH is adjusted to 1.0 by adding nitric acid, and a 500 W mercury lamp is used. Then, ultraviolet rays were irradiated for 24 hours (0.1 W / cm 2 ) to obtain Pt · PbO 2 -supported titanium oxide particles. The powder color changed from gray to brown by ultraviolet irradiation. This shows that Pb 2+ ions were oxidized by Pt-supported titanium oxide particles and precipitated as PbO 2 .
Ｐｔ・ＰｂＯ2担持酸化チタン粒子について走査型電子顕微鏡（ＳＥＭ）、エネルギー分散型蛍光Ｘ線分析装置（ＥＤＸ）、及び透過型電子顕微鏡（ＴＥＭ）を使用して確認した。その結果、Ｐｔは酸化チタン粒子の（１１０）面に担持され、ＰｂＯ2は（１１１）面に担持されていることが確認できた。このことから、（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子の（１１０）面は還元反応面、（１１１）面は酸化反応面であることが確認された（図４）。 The Pt / PbO 2 -supported titanium oxide particles were confirmed using a scanning electron microscope (SEM), an energy dispersive X-ray fluorescence spectrometer (EDX), and a transmission electron microscope (TEM). As a result, it was confirmed that Pt was supported on the (110) face of the titanium oxide particles and PbO 2 was supported on the (111) face. From this, it was confirmed that the (110) plane of the rod-shaped rutile-type titanium oxide particles having the (110) (111) plane is a reduction reaction plane and the (111) plane is an oxidation reaction plane (FIG. 4).
調製例２
テフロン（登録商標）塗装されたオートクレーブに、ＴｉＣｌ3（０．１５Ｍ）、ＮａＣｌ（５Ｍ）、及びポリビニルピロリドン（商品名「ＰＶＰ−Ｋ３０」、和光純薬工業（株）製、分子量：４００００、０．２５ｍＭ）を含む５０ｍＬ水溶液を仕込み、水熱処理（１８０℃、１０時間）を行った。得られた反応物を遠心分離し、脱イオン水でリンスし、真空乾燥機（バキュームオーブン）で乾燥して、酸化チタン粒子を得た。得られた酸化チタン粒子を透過型電子顕微鏡（ＴＥＭ）で確認したところ、（００１）（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子（比表面積：３５ｍ2／ｇ）であった（図５）。
Preparation Example 2
To an autoclave coated with Teflon (registered trademark), TiCl 3 (0.15M), NaCl (5M), and polyvinylpyrrolidone (trade name “PVP-K30”, manufactured by Wako Pure Chemical Industries, Ltd., molecular weight: 40000, 0 .. 50 mM aqueous solution containing 25 mM) was prepared, and hydrothermal treatment (180 ° C., 10 hours) was performed. The obtained reaction product was centrifuged, rinsed with deionized water, and dried with a vacuum dryer (vacuum oven) to obtain titanium oxide particles. When the obtained titanium oxide particles were confirmed by a transmission electron microscope (TEM), they were rod-shaped rutile titanium oxide particles (specific surface area: 35 m 2 / g) having (001) (110) (111) faces. (FIG. 5).
得られた（００１）（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子について、調製例１で得られたロッド状ルチル型酸化チタン粒子と同様の評価を行った結果、Ｐｔは酸化チタン粒子の（１１０）面に担持され、ＰｂＯ2は（００１）（１１１）面に担持されることが確認できた。このことから、（００１）（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子の（１１０）面は還元反応面、（００１）（１１１）面は酸化反応面であることが確認された（図６）。 The rod-shaped rutile type titanium oxide particles having the (001) (110) (111) face obtained were evaluated in the same manner as the rod-shaped rutile type titanium oxide particles obtained in Preparation Example 1. As a result, Pt was oxidized. It was confirmed that PbO 2 was supported on the (001) (111) plane and supported on the (110) plane of the titanium particles. From this, it was confirmed that the (110) plane of the rod-shaped rutile type titanium oxide particles having the (001) (110) (111) plane is a reduction reaction plane and the (001) (111) plane is an oxidation reaction plane. (FIG. 6).
調製例３
室温（２５℃）にて、市販のＴｉＣｌ4水溶液（和光純薬社製試薬化学用、約１６．５％Ｔｉ含有希塩酸溶液）を、Ｔｉ濃度が５．４重量％になるようにイオン交換水で希釈した。この希釈後のＴｉＣｌ4水溶液 ５６ｇをテフロン（登録商標）塗装された容量１００ｍｌのオートクレーブに入れ密閉した。上記オートクレーブをオイルバスに投入し、３０分間かけて、オートクレーブ内におけるＴｉＣｌ4水溶液の温度を１８０℃まで昇温した。その後、反応温度１８０℃、反応圧力 １．０ＭＰａの条件で、１０時間保持した後、オートクレーブを氷水につけて冷却した。３分後、オートクレーブ内におけるＴｉＣｌ4水溶液の温度が３０℃以下になったことを確認した後、オートクレーブを開封し、反応物を取り出した。１０℃にて、得られた反応物を遠心分離し、脱イオン水でリンスし、内温６５℃の真空乾燥機（バキュームオーブン）で１２時間減圧で乾燥して、５．２ｇの酸化チタン粒子を得た。得られた酸化チタン粒子を透過型電子顕微鏡（ＴＥＭ）で確認したところ、結晶面（００１）（１１０）（１１１）を有するロッド状ルチル型酸化チタン粒子（比表面積：５６ｍ2／ｇ）であった。
Preparation Example 3
At room temperature (25 ° C.), a commercially available TiCl 4 aqueous solution (for reagent chemistry manufactured by Wako Pure Chemical Industries, Ltd., dilute hydrochloric acid solution containing about 16.5% Ti) is ion-exchanged water so that the Ti concentration becomes 5.4% by weight. Diluted with 56 g of this diluted TiCl 4 aqueous solution was placed in a 100 ml autoclave coated with Teflon (registered trademark) and sealed. The autoclave was put into an oil bath, and the temperature of the TiCl 4 aqueous solution in the autoclave was raised to 180 ° C. over 30 minutes. Then, after maintaining for 10 hours under conditions of a reaction temperature of 180 ° C. and a reaction pressure of 1.0 MPa, the autoclave was cooled in ice water. After 3 minutes, after confirming that the temperature of the TiCl 4 aqueous solution in the autoclave was 30 ° C. or lower, the autoclave was opened and the reaction product was taken out. The obtained reaction product is centrifuged at 10 ° C., rinsed with deionized water, dried in a vacuum dryer (vacuum oven) at an internal temperature of 65 ° C. under reduced pressure for 12 hours, and 5.2 g of titanium oxide particles. Got. When the obtained titanium oxide particles were confirmed with a transmission electron microscope (TEM), they were rod-shaped rutile titanium oxide particles having a crystal plane (001) (110) (111) (specific surface area: 56 m 2 / g). It was.
調製例４
室温（２５℃）にて、市販のＴｉＣｌ4水溶液（和光純薬社製試薬化学用、約１６．５％Ｔｉ含有希塩酸溶液）４．８ｇに塩酸 ４．１ｇ、イオン交換水 ４３．１ｇを添加し、Ｔｉ濃度が１．５重量％、塩酸濃度が５．７重量％になるように濃度調整を行った。この調整後の水溶液 ５２ｇをテフロン（登録商標）塗装された容量１００ｍｌのオートクレーブに入れ密閉した。上記オートクレーブをオイルバスに投入し、３０分間かけて、オートクレーブ内におけるＴｉＣｌ4水溶液の温度を１８０℃まで昇温した。その後、反応温度１８０℃、反応圧力 １．０ＭＰａの条件で、１０時間保持した後、オートクレーブを氷水につけて冷却した。３分後、オートクレーブ内におけるＴｉＣｌ4水溶液の温度が３０℃以下になったことを確認した後、オートクレーブを開封し、反応物を取り出した。１０℃にて、得られた反応物を遠心分離し、脱イオン水でリンスし、内温６５℃の真空乾燥機（バキュームオーブン）で１２時間減圧で乾燥して１．１ｇの酸化チタン粒子を得た。得られた酸化チタン粒子を観察したところ、結晶面（００１）（１１０）（１１１）を有するロッド状ルチル型酸化チタン粒子（比表面積：４８ｍ2／ｇ）であった。
Preparation Example 4
At room temperature (25 ° C.), 4.1 g of hydrochloric acid and 43.1 g of ion-exchanged water were added to 4.8 g of a commercially available TiCl 4 aqueous solution (for reagent chemistry manufactured by Wako Pure Chemical Industries, Ltd., dilute hydrochloric acid solution containing about 16.5% Ti). The concentration was adjusted so that the Ti concentration was 1.5% by weight and the hydrochloric acid concentration was 5.7% by weight. 52 g of this adjusted aqueous solution was placed in an autoclave with a capacity of 100 ml coated with Teflon (registered trademark) and sealed. The autoclave was put into an oil bath, and the temperature of the TiCl 4 aqueous solution in the autoclave was raised to 180 ° C. over 30 minutes. Then, after maintaining for 10 hours under conditions of a reaction temperature of 180 ° C. and a reaction pressure of 1.0 MPa, the autoclave was cooled in ice water. After 3 minutes, after confirming that the temperature of the TiCl 4 aqueous solution in the autoclave was 30 ° C. or lower, the autoclave was opened and the reaction product was taken out. The obtained reaction product is centrifuged at 10 ° C., rinsed with deionized water, and dried in a vacuum dryer (vacuum oven) with an internal temperature of 65 ° C. under reduced pressure for 12 hours to obtain 1.1 g of titanium oxide particles. Obtained. When the obtained titanium oxide particles were observed, they were rod-shaped rutile type titanium oxide particles having a crystal plane (001) (110) (111) (specific surface area: 48 m 2 / g).
調製例５
市販のＴｉＣｌ4水溶液 ４．８ｇに塩酸 １２．３ｇ、イオン交換水 ４３．１ｇを添加し、Ｔｉ濃度が１．５重量％、塩酸濃度が１１．２重量％となるように濃度調整を行った以外は調製例４と同様にして、１．０ｇの酸化チタン粒子を得た。
Preparation Example 5
To 4.8 g of a commercially available TiCl 4 aqueous solution, 12.3 g of hydrochloric acid and 43.1 g of ion-exchanged water were added, and the concentration was adjusted so that the Ti concentration was 1.5 wt% and the hydrochloric acid concentration was 11.2 wt%. Except that, 1.0 g of titanium oxide particles was obtained in the same manner as in Preparation Example 4.
調製例６
市販のＴｉＣｌ4水溶液 ９．６ｇに塩酸 ８．２ｇ、イオン交換水 ３５．５ｇを添加し、Ｔｉ濃度が２．９重量％、塩酸濃度が１１．２重量％となるように濃度調整を行った以外は調製例４と同様にして、２．２ｇの酸化チタン粒子を得た。
Preparation Example 6
To 9.6 g of a commercially available TiCl 4 aqueous solution, 8.2 g of hydrochloric acid and 35.5 g of ion-exchanged water were added, and the concentration was adjusted so that the Ti concentration was 2.9 wt% and the hydrochloric acid concentration was 11.2 wt%. Except that, 2.2 g of titanium oxide particles were obtained in the same manner as in Preparation Example 4.
調製例７
市販のＴｉＣｌ4水溶液 ９．６ｇに塩酸 １６．４ｇ、イオン交換水 ３５．５ｇを添加し、Ｔｉ濃度が２．９重量％、塩酸濃度が１６．７重量％となるように濃度調整を行った以外は調製例４と同様にして、２．０ｇの酸化チタン粒子を得た。
Preparation Example 7
16.4 g of hydrochloric acid and 35.5 g of ion-exchanged water were added to 9.6 g of a commercially available TiCl 4 aqueous solution, and the concentration was adjusted so that the Ti concentration was 2.9 wt% and the hydrochloric acid concentration was 16.7 wt%. Except that, 2.0 g of titanium oxide particles were obtained in the same manner as in Preparation Example 4.
調製例８
市販のＴｉＣｌ4水溶液 １９．１ｇに塩酸 ８．２ｇ、イオン交換水 ３０．６ｇを添加し、Ｔｉ濃度が５．３重量％、塩酸濃度が１５．３重量％となるように濃度調整を行った以外は調製例４と同様にして、４．８ｇの酸化チタン粒子を得た。
Preparation Example 8
To 19.1 g of a commercially available TiCl 4 aqueous solution, 8.2 g of hydrochloric acid and 30.6 g of ion-exchanged water were added, and the concentration was adjusted so that the Ti concentration was 5.3 wt% and the hydrochloric acid concentration was 15.3% wt. Except that, 4.8 g of titanium oxide particles were obtained in the same manner as in Preparation Example 4.
調製例９
市販のＴｉＣｌ4水溶液 １９．１ｇに塩酸 １６．４ｇ、イオン交換水 ３０．６ｇを添加し、Ｔｉ濃度が５．３重量％、塩酸濃度が２０．２重量％となるように濃度調整を行った以外は調製例４と同様にして、４．５ｇの酸化チタン粒子を得た。
Preparation Example 9
16.4 g of hydrochloric acid and 30.6 g of ion-exchanged water were added to 19.1 g of a commercially available TiCl 4 aqueous solution, and the concentration was adjusted so that the Ti concentration was 5.3 wt% and the hydrochloric acid concentration was 20.2 wt%. Except that, 4.5 g of titanium oxide particles were obtained in the same manner as in Preparation Example 4.
調製例１０
チタニウム（IV）エトキシドを加水分解することによって得られたチタニアゾルを減圧乾燥した後、過酸化水素水を添加して、ペルオキソチタン酸水溶液を得た。その後、ポリビニルアルコール（和光純薬工業（株）製、分子量：２２０００、２．７ｍＭ）を加え、アンモニア水を加えてｐＨを７とし、６０℃で１２時間撹拌して、続いて水熱処理（２００℃、４８時間）を施した。得られた反応物を遠心分離し、脱イオン水でリンスし、真空乾燥機（バキュームオーブン）で乾燥して、酸化チタン粒子を得た。得られた酸化チタン粒子を透過型電子顕微鏡（ＴＥＭ）で確認したところ、（００１）（１０１）面を有するアナターゼ型酸化チタン粒子（比表面積：５７ｍ2／ｇ）であった（図７）。
Preparation Example 10
A titania sol obtained by hydrolyzing titanium (IV) ethoxide was dried under reduced pressure, and then a hydrogen peroxide solution was added to obtain a peroxotitanic acid aqueous solution. Thereafter, polyvinyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight: 22000, 2.7 mM) was added, aqueous ammonia was added to adjust the pH to 7, and the mixture was stirred at 60 ° C. for 12 hours, followed by hydrothermal treatment (200 (C, 48 hours). The obtained reaction product was centrifuged, rinsed with deionized water, and dried with a vacuum dryer (vacuum oven) to obtain titanium oxide particles. When the obtained titanium oxide particles were confirmed with a transmission electron microscope (TEM), they were anatase-type titanium oxide particles having a (001) (101) plane (specific surface area: 57 m 2 / g) (FIG. 7).
得られた（００１）（１０１）面を有するアナターゼ型酸化チタン粒子について、調製例１において得られたロッド状ルチル型酸化チタン粒子に行ったのと同様の評価を行った結果、Ｐｔは酸化チタン粒子の（１０１）面に担持され、ＰｂＯ2は（００１）面に担持されることが確認できた。このことから、（００１）（１０１）面を有するアナターゼ型酸化チタン粒子の（１０１）面は還元反応面、（００１）面は酸化反応面であることが確認された（図８）。 The obtained anatase-type titanium oxide particles having the (001) (101) surface were evaluated in the same manner as the rod-shaped rutile-type titanium oxide particles obtained in Preparation Example 1. As a result, Pt was titanium oxide. It was confirmed that the particles were supported on the (101) plane and PbO 2 was supported on the (001) plane. From this, it was confirmed that the (101) plane of the anatase-type titanium oxide particles having the (001) (101) plane is a reduction reaction plane and the (001) plane is an oxidation reaction plane (FIG. 8).
実施例１
（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子をイオン交換水に分散させ、１．０ｍＷｃｍ-2に調節された高圧水銀ランプの光照射下で、撹拌しながら酸化チタン粒子に対し鉄イオンが０．１０重量％になるように調製された硝酸鉄（III）水溶液を加えた。６時間後、粒子を遠心分離により回収し、イオン交換水でイオン伝導度が６ｕＳｃｍ-2以下になるまで洗浄し、真空乾燥することにより、鉄イオン担持酸化チタン粒子（１）を得た。
得られた鉄イオン担持酸化チタン粒子（１）を走査型電子顕微鏡（ＳＥＭ）、エネルギー分散型蛍光Ｘ線分析装置（ＥＤＸ）、及び透過型電子顕微鏡（ＴＥＭ）で確認したところ、（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子の（１１１）面に鉄イオン（III）が選択的に担持されていた［被覆率：２．５％、（１１１）面選択率：９０％］（図９）。
Example 1
Disperse rod-shaped rutile-type titanium oxide particles having (110) (111) faces in ion-exchanged water, and with respect to the titanium oxide particles while stirring under light irradiation of a high-pressure mercury lamp adjusted to 1.0 mWcm −2. An iron (III) nitrate aqueous solution prepared so that the iron ion was 0.10% by weight was added. After 6 hours, the particles were collected by centrifugation, washed with ion-exchanged water until the ion conductivity became 6 uScm -2 or less, and vacuum-dried to obtain iron ion-supported titanium oxide particles (1).
The obtained iron ion-carrying titanium oxide particles (1) were confirmed with a scanning electron microscope (SEM), an energy dispersive X-ray fluorescence spectrometer (EDX), and a transmission electron microscope (TEM). Iron ions (III) were selectively supported on the (111) face of rod-shaped rutile-type titanium oxide particles having a (111) face [coverage: 2.5%, (111) face selectivity: 90%] (FIG. 9).
比較例１
高圧水銀ランプの光照射を行わなかった以外は実施例１と同様にして、鉄イオン担持酸化チタン粒子（２）を得た。
得られた鉄イオン担持酸化チタン粒子（２）を走査型電子顕微鏡（ＳＥＭ）、エネルギー分散型蛍光Ｘ線分析装置（ＥＤＸ）、及び透過型電子顕微鏡（ＴＥＭ）で確認したところ、（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子表面全体に鉄イオン（III）が担持されていた［被覆率：２．５％］（図１０）。
Comparative Example 1
Iron ion-carrying titanium oxide particles (2) were obtained in the same manner as in Example 1 except that the high-pressure mercury lamp was not irradiated with light.
The obtained iron ion-carrying titanium oxide particles (2) were confirmed with a scanning electron microscope (SEM), an energy dispersive X-ray fluorescence spectrometer (EDX), and a transmission electron microscope (TEM). Iron ions (III) were supported on the entire surface of rod-shaped rutile-type titanium oxide particles having a (111) face [coverage: 2.5%] (FIG. 10).
実施例２
イオン交換水に分散させる代わりに、１．５体積％のエタノール水溶液に分散させて鉄イオンを担持させた以外は実施例１と同様にして、鉄イオン担持酸化チタン粒子（３）を得た。
得られた鉄イオン担持酸化チタン粒子（３）を走査型電子顕微鏡（ＳＥＭ）、エネルギー分散型蛍光Ｘ線分析装置（ＥＤＸ）、及び透過型電子顕微鏡（ＴＥＭ）で確認したところ、（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子の（１１１）面に鉄イオン（III）が選択的に担持されていた［被覆率：２．５％、（１１１）面選択率：９５％］（図１１）。
Example 2
Instead of being dispersed in ion-exchanged water, iron ion-supported titanium oxide particles (3) were obtained in the same manner as in Example 1 except that iron ions were supported by being dispersed in a 1.5% by volume ethanol aqueous solution.
When the obtained iron ion-supporting titanium oxide particles (3) were confirmed by a scanning electron microscope (SEM), an energy dispersive X-ray fluorescence spectrometer (EDX), and a transmission electron microscope (TEM), (110) ( Iron ions (III) were selectively supported on the (111) face of rod-shaped rutile-type titanium oxide particles having a 111) face [coverage: 2.5%, (111) face selectivity: 95%] (FIG. 11).
実施例３
（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子の代わりに、（００１）（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子を使用した以外は実施例２と同様にして、鉄イオン担持酸化チタン粒子（４）を得た。
得られた鉄イオン担持酸化チタン粒子（４）を走査型電子顕微鏡（ＳＥＭ）、エネルギー分散型蛍光Ｘ線分析装置（ＥＤＸ）、及び透過型電子顕微鏡（ＴＥＭ）で確認したところ、（００１）（１１０）（１１１）面を有するロッド状ルチル型酸化チタン粒子の（００１）（１１１）面に鉄イオン（III）が選択的に担持されていた［被覆率：２．５％、（００１）（１１１）面選択率：９５％］。
Example 3
Example 2 was used except that rod-shaped rutile titanium oxide particles having (001) (110) (111) surfaces were used instead of rod-shaped rutile titanium oxide particles having (110) (111) surfaces. As a result, iron ion-supported titanium oxide particles (4) were obtained.
When the obtained iron ion-supporting titanium oxide particles (4) were confirmed by a scanning electron microscope (SEM), an energy dispersive X-ray fluorescence spectrometer (EDX), and a transmission electron microscope (TEM), (001) ( The iron ion (III) was selectively supported on the (001) (111) surface of the rod-shaped rutile-type titanium oxide particles having (110) (111) surface [coverage: 2.5%, (001) ( 111) Plane selectivity: 95%].
実施例４
酸化チタン粒子に対する鉄イオン濃度を０．１０重量％から０．０５重量％に代えて調製された硝酸鉄（III）水溶液を使用した以外は実施例１と同様にして、鉄イオン担持酸化チタン粒子（５）［被覆率：１．０％、（１１１）面選択率：９０％］を得た。
Example 4
Iron ion-carrying titanium oxide particles in the same manner as in Example 1 except that an iron (III) nitrate aqueous solution prepared by changing the iron ion concentration with respect to titanium oxide particles from 0.10 wt% to 0.05 wt% was used. (5) [Coating rate: 1.0%, (111) plane selectivity: 90%] was obtained.
実施例５
酸化チタン粒子に対する鉄イオン濃度を０．１０重量％から１．００重量％に代えて調製された硝酸鉄（III）水溶液を使用した以外は実施例１と同様にして、鉄イオン担持酸化チタン粒子（６）［被覆率：８．０％、（１１１）面選択率：９０％］を得た。
Example 5
Iron ion-carrying titanium oxide particles in the same manner as in Example 1 except that an iron (III) nitrate aqueous solution prepared by changing the iron ion concentration with respect to titanium oxide particles from 0.10% by weight to 1.00% by weight was used. (6) [Coating rate: 8.0%, (111) plane selectivity: 90%] was obtained.
実施例６
（００１）（１１０）（１１１）面を有するルチル型酸化チタン粒子 １．５ｇを３．０体積％のメタノール水溶液 １０ｍｌに分散させて、１．０ｍＷｃｍ-2に調節されたＵＶ−ＬＥＤの光照射下で、撹拌しながら酸化チタン粒子に対し鉄イオンが０．２重量％になるように調整された塩化鉄（III）水溶液を加えた。６時間後、粒子を遠心分離により回収し、イオン交換水でイオン伝導度が６ｕＳｃｍ-2以下になるまで洗浄し、真空乾燥することにより、鉄イオン担持酸化チタン粒子（７）［被覆率：４．７％、（００１）（１１１）面選択率：９０％］を得た。
Example 6
Irradiation of UV-LED adjusted to 1.0 mWcm −2 by dispersing 1.5 g of rutile-type titanium oxide particles having (001) (110) (111) plane in 10 ml of 3.0 vol% methanol aqueous solution. Under stirring, an aqueous iron (III) chloride solution adjusted so that the iron ion was 0.2% by weight with respect to the titanium oxide particles was added. After 6 hours, the particles were collected by centrifugation, washed with ion-exchanged water until the ionic conductivity was 6 uScm -2 or less, and vacuum-dried, whereby iron ion-carrying titanium oxide particles (7) [coverage: 4 0.7%, (001) (111) plane selectivity: 90%].
実施例７
（００１）（１１０）（１１１）面を有するルチル型酸化チタン粒子 １５０ｇを３．０体積％のメタノール水溶液 １０００ｍｌに分散させて、１．０ｍＷｃｍ-2に調節されたブラックライトの光照射下で、酸化チタン粒子に対し鉄イオンが０．２重量％になるように塩化鉄０．８７ｇ加えた。６時間後、粒子を遠心分離により回収し、イオン交換水でイオン伝導度が６ｕＳｃｍ-2以下になるまで洗浄し、真空乾燥することにより、鉄イオン担持酸化チタン粒子（８）［被覆率：４．７％、（００１）（１１１）面選択率：９０％］を得た。
Example 7
150 g of rutile-type titanium oxide particles having a (001) (110) (111) plane were dispersed in 1000 ml of a 3.0% by volume methanol aqueous solution, and under the light irradiation of black light adjusted to 1.0 mWcm −2 , 0.87 g of iron chloride was added so that iron ions might be 0.2% by weight with respect to the titanium oxide particles. After 6 hours, the particles were collected by centrifugation, washed with ion-exchanged water until the ionic conductivity was 6 uScm -2 or less, and vacuum-dried, whereby iron ion-carrying titanium oxide particles (8) [coverage: 4 0.7%, (001) (111) plane selectivity: 90%].
実施例８
１．０ｍＷｃｍ-2に調節されたブラックライトに代えて、４２ｍＷｃｍ-2に調節された高圧水銀ランプ（商品名「ＨＬ１００ＣＨ−４」、セン特殊光源株式会社製）を使用した以外は実施例７と同様にして、鉄イオン担持酸化チタン粒子（９）［被覆率：４．７％、（００１）（１１１）面選択率：９０％］を得た。
Example 8
Example 7 except that a high-pressure mercury lamp adjusted to 42 mWcm -2 (trade name “HL100CH-4”, manufactured by Sen Special Light Source Co., Ltd.) was used instead of the black light adjusted to 1.0 mWcm −2. Similarly, iron ion-supported titanium oxide particles (9) [coverage ratio: 4.7%, (001) (111) plane selectivity: 90%] were obtained.
実施例９
（００１）（１１０）（１１１）面を有するルチル型酸化チタン粒子に代えて、（００１）（１０１）面を有するアナターゼ型酸化チタン粒子 １５０ｇを使用した以外は実施例７と同様にして、鉄イオン担持酸化チタン粒子（１０）を得た。得られた鉄イオン担持酸化チタン粒子（１０）を走査型電子顕微鏡（ＳＥＭ）、エネルギー分散型蛍光Ｘ線分析装置（ＥＤＸ）、及び透過型電子顕微鏡（ＴＥＭ）で確認したところ、（００１）（１０１）面を有するアナターゼ型酸化チタン粒子の（００１）面に鉄イオン（III）が選択的に担持されていた［被覆率：２．８％、（００１）面選択率：９０％］。
Example 9
In the same manner as in Example 7, except that 150 g of anatase-type titanium oxide particles having (001) (101) face were used instead of rutile-type titanium oxide particles having (001) (110) (111) face, iron was used. Ion-supported titanium oxide particles (10) were obtained. The obtained iron ion-carrying titanium oxide particles (10) were confirmed with a scanning electron microscope (SEM), an energy dispersive X-ray fluorescence spectrometer (EDX), and a transmission electron microscope (TEM). 101) Iron ions (III) were selectively supported on the (001) face of anatase-type titanium oxide particles having a face [coverage: 2.8%, (001) face selectivity: 90%].
実施例及び比較例で得られた鉄イオン担持酸化チタン粒子について、気相にてトルエン（又は、アセトアルデヒド）を酸化し、生成するＣＯ2量を測定することにより光触媒活性を評価した。 For iron ions supporting titanium oxide particles obtained in Examples and Comparative Examples, toluene in the gas phase (or acetaldehyde) was oxidized to evaluate the photocatalytic activity by measuring the produced amount of CO 2.
テドラーバッグ（アズワン（株）社製）を反応容器として使用した。実施例及び比較例で得られた鉄イオン担持酸化チタン粒子、調製例１で調製したロッド状ルチル型酸化チタン粒子（鉄イオン非担持酸化チタン粒子）、及び窒素ドープ酸化チタン（商品名「ＴＰ−Ｓ２０１」、住友化学（株）製、比表面積８０ｍ2／ｇ）０．１ｇをそれぞれガラス製皿に広げた状態で反応容器の中に入れ、５００ｐｐｍのトルエン（又は、アセトアルデヒド）飽和ガスを反応容器に吹き込んだ。ガスとトルエン（又は、アセトアルデヒド）が平衡に達した後、室温（２５℃）で光照射を行った。光源には青色ＬＥＤ（商品名「LXHL-MRRC」、Lumileds Lighting社製）を使用し、可視光線域の光（波長４５５ｎｍ）を照射した（光量：１ｍＷ／ｃｍ2）。 A Tedlar bag (manufactured by As One Co., Ltd.) was used as a reaction vessel. Iron ion-supported titanium oxide particles obtained in Examples and Comparative Examples, rod-shaped rutile-type titanium oxide particles (iron ion-non-supported titanium oxide particles) prepared in Preparation Example 1, and nitrogen-doped titanium oxide (trade name “TP- S201 ", manufactured by Sumitomo Chemical Co., Ltd., with a specific surface area of 80 m 2 / g) 0.1 g each was spread on a glass plate and placed in a reaction vessel, and 500 ppm of toluene (or acetaldehyde) saturated gas was added to the reaction vessel. Infused into. After the gas and toluene (or acetaldehyde) reached equilibrium, light irradiation was performed at room temperature (25 ° C.). A blue LED (trade name “LXHL-MRRC”, manufactured by Lumileds Lighting) was used as a light source, and light in the visible light range (wavelength 455 nm) was irradiated (light amount: 1 mW / cm 2 ).
光照射開始後、ＣＯ2の生成量をメタナイザーが付属した水素炎イオン化検出器付きガスクロマトグラフ（商品名「ＧＣ−８Ａ」、「ＧＣ−１４Ａ」、島津製作所製）を使用して測定した（図１２、１３、１４、１５）。 After the light irradiation was started, the amount of CO 2 produced was measured using a gas chromatograph with a flame ionization detector (trade names “GC-8A”, “GC-14A”, manufactured by Shimadzu Corporation) attached with a methanizer. 12, 13, 14, 15).
さらに、光源としてＵＶ−ＬＥＤ（商品名「NCSU033A」、日亜化学(株)製）を使用し、紫外線域の光（波長３６５ｎｍ）を照射（光量：１ｍＷ／ｃｍ2）した以外は上記と同様にして、ＣＯ2の生成量を測定したところ、可視光照射の場合と同様の結果が得られた。 Furthermore, UV-LED (trade name “NCSU033A”, manufactured by Nichia Corporation) was used as a light source, and was irradiated with light in the ultraviolet region (wavelength 365 nm) (light quantity: 1 mW / cm 2 ). Then, when the amount of CO 2 produced was measured, the same result as in the case of irradiation with visible light was obtained.
以上より、励起光照射下で露出結晶面を有する酸化チタン粒子に遷移金属イオンを担持させると、遷移金属イオンは２以上の露出結晶面のうち酸化反応面（例えば、鉄イオンの場合）或いは還元反応面（例えば、白金含有イオンの場合）に選択的に担持されることが分かる。また、その面選択性は、犠牲剤を添加することにより向上することが分かる。
そして、遷移金属イオンが担持された酸化チタン粒子は、紫外線域から可視光線域までの広い有効波長範囲に応答性を有する。その上、面選択的に遷移金属イオンが担持された酸化チタン粒子は、非選択的に遷移金属イオンが担持された酸化チタン粒子に比べて、高い光触媒活性を発揮することができる。また、（１１０）（１１１）面とともに（００１）面をも有するロッド状ルチル型酸化チタン粒子は、既存の酸化反応面［（１１１）面]と共に（００１）面も酸化反応面として作用し、該（００１）面がより高い励起電子とホールの分離性を有するため、さらに優れた光触媒活性を発揮することができることが分かる。
As described above, when transition metal ions are supported on titanium oxide particles having exposed crystal planes under excitation light irradiation, transition metal ions are reduced in the oxidation reaction plane (for example, in the case of iron ions) or reduced among two or more exposed crystal planes. It can be seen that it is selectively supported on the reaction surface (for example, in the case of platinum-containing ions). Moreover, it turns out that the surface selectivity improves by adding a sacrificial agent.
The titanium oxide particles carrying transition metal ions are responsive in a wide effective wavelength range from the ultraviolet range to the visible light range. Moreover, titanium oxide particles on which transition metal ions are supported in a surface-selective manner can exhibit higher photocatalytic activity than titanium oxide particles on which transition metal ions are supported in a non-selective manner. In addition, the rod-shaped rutile type titanium oxide particles having the (110) (111) plane and the (001) plane both act as an oxidation reaction plane together with the existing oxidation reaction plane [(111) plane] and the (001) plane. It can be seen that since the (001) plane has a higher separation between excited electrons and holes, a further excellent photocatalytic activity can be exhibited.
以上より、酸化反応面と還元反応面とが空間的により大きく分離される露出結晶面を有する酸化チタン粒子に遷移金属イオンを面選択的に担持することにより、紫外線域から可視光線域までの広い波長範囲に応答性を付与することができるとともに、酸化チタン粒子表面における励起電子とホールの分離性を著しく高めることができ、励起電子とホールの再結合、及び、逆反応の進行を防止することができ、それにより酸化チタン粒子の触媒能を飛躍的に向上させることができることが明らかとなった。 As described above, the transition metal ions are supported on the titanium oxide particles having an exposed crystal plane in which the oxidation reaction surface and the reduction reaction surface are separated more spatially, so that a wide range from the ultraviolet region to the visible light region can be obtained. Responsiveness can be imparted to the wavelength range, and the separation of excited electrons and holes on the surface of titanium oxide particles can be remarkably enhanced, preventing recombination of excited electrons and holes and the progress of reverse reaction. It has become clear that the catalytic ability of the titanium oxide particles can be dramatically improved.
Claims (6)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010291673A JP5591683B2 (en) | 2010-01-09 | 2010-12-28 | Metal ion-supported titanium oxide particles having an exposed crystal face and method for producing the same |
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010003438 | 2010-01-09 | ||
| JP2010003438 | 2010-01-09 | ||
| JP2010081918 | 2010-03-31 | ||
| JP2010081918 | 2010-03-31 | ||
| JP2010291673A JP5591683B2 (en) | 2010-01-09 | 2010-12-28 | Metal ion-supported titanium oxide particles having an exposed crystal face and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2011225422A JP2011225422A (en) | 2011-11-10 |
| JP5591683B2 true JP5591683B2 (en) | 2014-09-17 |
Family
ID=45041296
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2010291673A Active JP5591683B2 (en) | 2010-01-09 | 2010-12-28 | Metal ion-supported titanium oxide particles having an exposed crystal face and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5591683B2 (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6053676B2 (en) | 2011-06-07 | 2016-12-27 | 株式会社ダイセル | Photocatalyst coating film and method for producing the same |
| JP5919019B2 (en) * | 2012-02-14 | 2016-05-18 | 株式会社ダイセル | Visible light responsive photocatalyst member and apparatus |
| JP6046732B2 (en) * | 2012-09-19 | 2016-12-21 | 株式会社ダイセル | Method for producing transition metal compound-supported titanium oxide suspension, and method for producing transition metal compound-supported titanium oxide |
| WO2014046020A1 (en) * | 2012-09-19 | 2014-03-27 | 株式会社ダイセル | Transition metal compound-loaded titanium oxide |
| JP6231550B2 (en) * | 2013-03-15 | 2017-11-15 | 株式会社ダイセル | Titanium oxide dispersion, titanium oxide coating solution, and photocatalytic coating |
| JP6315791B2 (en) * | 2014-01-21 | 2018-04-25 | 株式会社ダイセル | Iron compound-supported titanium oxide particles |
| JP6263082B2 (en) * | 2014-01-23 | 2018-01-17 | 株式会社ダイセル | Antimicrobial agent for dark places |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002114517A (en) * | 2000-08-01 | 2002-04-16 | Ishihara Sangyo Kaisha Ltd | Metal oxide and method for producing the same |
| JP2009227515A (en) * | 2008-03-24 | 2009-10-08 | Teruhisa Yokono | Method for producing titanium oxide particle and titanium oxide particle |
| JP5498009B2 (en) * | 2008-10-30 | 2014-05-21 | 国立大学法人 東京大学 | Photocatalyst material, organic matter decomposition method, interior member, air cleaning device, oxidizer manufacturing device |
-
2010
- 2010-12-28 JP JP2010291673A patent/JP5591683B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2011225422A (en) | 2011-11-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Dong et al. | Facile synthesis of In2S3/UiO-66 composite with enhanced adsorption performance and photocatalytic activity for the removal of tetracycline under visible light irradiation | |
| JP5711582B2 (en) | Photocatalyst and organic compound oxidation method using the same | |
| Xu et al. | Unveiling the role of defects on oxygen activation and photodegradation of organic pollutants | |
| JP5591683B2 (en) | Metal ion-supported titanium oxide particles having an exposed crystal face and method for producing the same | |
| Jiang et al. | Constructing graphite-like carbon nitride modified hierarchical yolk–shell TiO 2 spheres for water pollution treatment and hydrogen production | |
| JP5129897B1 (en) | Copper compound-supported titanium oxide photocatalyst and method for producing the same | |
| JP6342225B2 (en) | Photocatalyst composite material and method for producing the same | |
| Bhattacharyya et al. | Effect of vanadia doping and its oxidation state on the photocatalytic activity of TiO2 for gas-phase oxidation of ethene | |
| Xu et al. | Enhanced photocatalytic activity of Ag3VO4 loaded with rare-earth elements under visible-light irradiation | |
| KR101334970B1 (en) | Photocatalyst material, method for decomposition of organic material, interior member, air purification device, and appatarus for preparation of oxidizing agent | |
| Anandan et al. | [Retracted] Highly Active Rare‐Earth‐Metal La‐Doped Photocatalysts: Fabrication, Characterization, and Their Photocatalytic Activity | |
| CN109759110A (en) | A kind of N doping porous carbon loaded titanium dioxide photocatalyst and the preparation method and application thereof | |
| TWI476043B (en) | Photocatalytic materials and process for producing the same | |
| JPWO2006064799A1 (en) | Composite metal oxide photocatalyst with visible light response | |
| Sun et al. | Synthesis, characterization of Ce-doped TiO 2 nanotubes with high visible light photocatalytic activity | |
| TW201026384A (en) | Photocatalytic material, method of decomposing organic substance, interior member, air cleaning device, and device for producing oxidizing agent | |
| Liu et al. | Superb photocatalytic activity of 2D/2D Cl doped g-C3N4 nanodisc/Bi2WO6 nanosheet heterojunction: Exploration of photoinduced carrier migration in S-scheme heterojunction | |
| KR101421572B1 (en) | Photocatalyst comprising TiO2-porphyrin derivatives complex and method for preparing the same | |
| Liang et al. | Hydroxyl/amino and Fe (III) co-grafted graphite carbon nitride for photocatalytic removal of volatile organic compounds | |
| Kuvarega et al. | Evaluation of the simulated solar light photocatalytic activity of N, Ir co-doped TiO2 for organic dye removal from water | |
| He et al. | Site-selective nitrogen-doped α-MnO2 for catalytic oxidation of carcinogenic HCHO in indoor air | |
| KR100578044B1 (en) | A method for fabrication of the visible-range photocatalyst with junction of titanium dioxide and tungsten oxide | |
| TWI272250B (en) | Visible light-activated photocatalyst and method for producing the same | |
| Yuan et al. | Photocatalytic Ag Nanoparticle Growth Induced Oxygen Vacancy Formation on Few-Layered BiOBr Nanosheets and Enhancements of· O2–Generation Toward Tetracycline Photodegradation | |
| Zhang et al. | Preparation of Ti mesh supported N–S–C-tridoped TiO 2 nanosheets to achieve high utilization of optical energy for photocatalytic degradation of norfloxacin |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20130906 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20140618 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20140624 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20140715 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20140729 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20140730 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5591683 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| S531 | Written request for registration of change of domicile |
Free format text: JAPANESE INTERMEDIATE CODE: R313531 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |