JP2000157874A - Titanium oxide photocatalyst and production thereof - Google Patents
Titanium oxide photocatalyst and production thereofInfo
- Publication number
- JP2000157874A JP2000157874A JP11265825A JP26582599A JP2000157874A JP 2000157874 A JP2000157874 A JP 2000157874A JP 11265825 A JP11265825 A JP 11265825A JP 26582599 A JP26582599 A JP 26582599A JP 2000157874 A JP2000157874 A JP 2000157874A
- Authority
- JP
- Japan
- Prior art keywords
- titanium oxide
- product
- water
- titanium
- present
- 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.)
- Granted
Links
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 title claims abstract description 77
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 title claims abstract description 60
- 239000011941 photocatalyst Substances 0.000 title claims abstract description 33
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 44
- 239000002244 precipitate Substances 0.000 claims abstract description 22
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims abstract description 15
- 239000010936 titanium Substances 0.000 claims abstract description 15
- 229910052719 titanium Inorganic materials 0.000 claims abstract description 15
- 238000010335 hydrothermal treatment Methods 0.000 claims description 11
- 239000013078 crystal Substances 0.000 claims description 10
- 239000007795 chemical reaction product Substances 0.000 claims description 8
- 239000002994 raw material Substances 0.000 claims description 8
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 6
- FIPWRIJSWJWJAI-UHFFFAOYSA-N Butyl carbitol 6-propylpiperonyl ether Chemical compound C1=C(CCC)C(COCCOCCOCCCC)=CC2=C1OCO2 FIPWRIJSWJWJAI-UHFFFAOYSA-N 0.000 claims description 3
- HHFAWKCIHAUFRX-UHFFFAOYSA-N ethoxide Chemical compound CC[O-] HHFAWKCIHAUFRX-UHFFFAOYSA-N 0.000 claims description 3
- 229960005235 piperonyl butoxide Drugs 0.000 claims description 3
- IKNCGYCHMGNBCP-UHFFFAOYSA-N propan-1-olate Chemical compound CCC[O-] IKNCGYCHMGNBCP-UHFFFAOYSA-N 0.000 claims description 3
- 230000001678 irradiating effect Effects 0.000 claims 1
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 abstract description 32
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 abstract description 24
- 229910052697 platinum Inorganic materials 0.000 abstract description 16
- 238000006243 chemical reaction Methods 0.000 abstract description 10
- 239000000203 mixture Substances 0.000 abstract description 7
- 239000010419 fine particle Substances 0.000 abstract description 3
- 239000000047 product Substances 0.000 description 52
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 33
- 238000002441 X-ray diffraction Methods 0.000 description 24
- 238000001027 hydrothermal synthesis Methods 0.000 description 15
- 239000000243 solution Substances 0.000 description 14
- 239000001257 hydrogen Substances 0.000 description 13
- 229910052739 hydrogen Inorganic materials 0.000 description 13
- 230000001699 photocatalysis Effects 0.000 description 13
- 230000004580 weight loss Effects 0.000 description 12
- 239000002253 acid Substances 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 11
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 10
- 238000000034 method Methods 0.000 description 10
- 239000004809 Teflon Substances 0.000 description 8
- 229920006362 Teflon® Polymers 0.000 description 8
- 239000007864 aqueous solution Substances 0.000 description 8
- 238000001914 filtration Methods 0.000 description 8
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 8
- 229910052753 mercury Inorganic materials 0.000 description 8
- 239000012153 distilled water Substances 0.000 description 7
- 238000006552 photochemical reaction Methods 0.000 description 7
- 230000035484 reaction time Effects 0.000 description 7
- 238000002425 crystallisation Methods 0.000 description 6
- 230000008025 crystallization Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000007789 gas Substances 0.000 description 6
- 238000010438 heat treatment 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
- 239000000126 substance Substances 0.000 description 5
- 238000005406 washing Methods 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical class [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 238000003786 synthesis reaction Methods 0.000 description 4
- 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 4
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 3
- 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 3
- 238000001816 cooling Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000004817 gas chromatography Methods 0.000 description 3
- 239000012452 mother liquor Substances 0.000 description 3
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 3
- 238000006303 photolysis reaction Methods 0.000 description 3
- 239000005297 pyrex Substances 0.000 description 3
- 238000006722 reduction reaction Methods 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- MKYBYDHXWVHEJW-UHFFFAOYSA-N N-[1-oxo-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)propan-2-yl]-2-[[3-(trifluoromethoxy)phenyl]methylamino]pyrimidine-5-carboxamide Chemical compound O=C(C(C)NC(=O)C=1C=NC(=NC=1)NCC1=CC(=CC=C1)OC(F)(F)F)N1CC2=C(CC1)NN=N2 MKYBYDHXWVHEJW-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 239000003153 chemical reaction reagent Substances 0.000 description 2
- 230000003301 hydrolyzing effect Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000011068 loading method Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 230000015843 photosynthesis, light reaction Effects 0.000 description 2
- HKJYVRJHDIPMQB-UHFFFAOYSA-N propan-1-olate;titanium(4+) Chemical compound CCCO[Ti](OCCC)(OCCC)OCCC HKJYVRJHDIPMQB-UHFFFAOYSA-N 0.000 description 2
- 239000007858 starting material Substances 0.000 description 2
- 238000002076 thermal analysis method Methods 0.000 description 2
- WWSJZGAPAVMETJ-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-3-ethoxypyrazol-1-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C=1C(=NN(C=1)CC(=O)N1CC2=C(CC1)NN=N2)OCC WWSJZGAPAVMETJ-UHFFFAOYSA-N 0.000 description 1
- FYELSNVLZVIGTI-UHFFFAOYSA-N 2-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]-5-ethylpyrazol-1-yl]-1-(2,4,6,7-tetrahydrotriazolo[4,5-c]pyridin-5-yl)ethanone Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C=1C=NN(C=1CC)CC(=O)N1CC2=C(CC1)NN=N2 FYELSNVLZVIGTI-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 238000004566 IR spectroscopy Methods 0.000 description 1
- -1 alkoxide titanate Chemical class 0.000 description 1
- 239000003708 ampul Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000000844 anti-bacterial effect Effects 0.000 description 1
- 230000003373 anti-fouling effect Effects 0.000 description 1
- 230000005587 bubbling Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000003426 co-catalyst Substances 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001877 deodorizing effect Effects 0.000 description 1
- 239000002274 desiccant Substances 0.000 description 1
- 238000004108 freeze drying Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 230000001443 photoexcitation Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 238000010532 solid phase synthesis reaction Methods 0.000 description 1
- 238000001694 spray drying Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、光触媒活性が高い
酸化チタン光触媒及びその製造方法に関するものであ
る。さらに詳しくいえば、本発明は、例えば、４００Ｗ
高圧水銀ランプによる紫外光照射下で本発明の光触媒
０. ３ｇ、メタノール水溶液（メタノール：水＝１：３
体積比）６００ｃｍ3 から毎時２００ｃｍ3 以上の水素
ガス発生量を示す光触媒活性が高い酸化チタン光触媒及
びこのものを効率よく製造する方法に関するものであ
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a titanium oxide photocatalyst having high photocatalytic activity and a method for producing the same. More specifically, the present invention is, for example, 400 W
0.3 g of a photocatalyst of the present invention and an aqueous methanol solution (methanol: water = 1: 3) under irradiation with ultraviolet light from a high-pressure mercury lamp.
To a method of photocatalytic activity to produce better high titanium oxide photocatalyst and efficiency this indicates a volume ratio) 600 cm 3 per hour 200 cm 3 or more hydrogen gas generation amount.
【０００２】[0002]
【従来の技術】酸化チタンは光照射による電荷分離を生
じ、光エネルギーを化学エネルギーに変換する水の光分
解触媒として従来から知られていたが、近年、電荷分離
により生じた正孔による酸化反応を利用し、有機物を分
解する脱臭・抗菌・防汚作用を有する光触媒として注目
されている。光触媒活性は、結晶型により差があること
が知られており、アナタース型酸化チタンの活性がもっ
とも高い傾向にある。しかし、結晶化に大気加熱処理を
施すと粒子径の増加などにより比表面積の低下が生じ、
活性が低下してしまうことが問題となっている。また、
アナタースへの結晶化には、４００℃以上の加熱処理が
必要であり、この際に多量の熱エネルギーを必要とする
ことから加熱処理操作に代わる穏和な条件下での合成プ
ロセスの開発が望まれている。2. Description of the Related Art Titanium oxide has been conventionally known as a photodecomposition catalyst for water that causes charge separation by light irradiation and converts light energy into chemical energy. It has been attracting attention as a photocatalyst that has the deodorizing, antibacterial, and antifouling effects of decomposing organic substances by utilizing organic compounds. It is known that the photocatalytic activity varies depending on the crystal type, and the activity of anatase-type titanium oxide tends to be the highest. However, when air heating treatment is applied to crystallization, the specific surface area decreases due to an increase in particle size, etc.
The problem is that the activity is reduced. Also,
Heat treatment at 400 ° C. or higher is required for crystallization to anatase. At this time, a large amount of heat energy is required. Therefore, it is desired to develop a synthesis process under mild conditions instead of the heat treatment operation. ing.
【０００３】近年、水熱合成法は従来の固相合成法では
高温条件下で得られるものがより穏和な温度条件下で合
成できるソフトケミストリープロセスとして注目されて
いる。水熱反応を利用してアモルファスなチタン酸化物
からアナタースを結晶化させる試みとしては、出発物質
としてチタニウムテトラエトキシドを加水分解して得ら
れた非晶質酸化チタンを用いた例が報告されている。水
を含まない加熱雰囲気では４００℃以上でアナタースへ
の結晶化が進行するのに対し、９８ｋＰａの水蒸気圧下
では２５０℃でアナタースへの結晶化が生じることが明
らかにされている。また、２５０℃の多量の水が存在す
る水熱条件下では、多くのアナタース結晶核が生成し、
それぞれの結晶核が大きく成長できないため、１１ｎｍ
程度の結晶が生成すると報告されている（高圧討論会予
稿集Ｐ３２０、ｐｐ１１７（１９９５））。しかしなが
ら、詳細な水熱温度条件及び得られたアナタース結晶の
光触媒活性の検討はなされていない。[0003] In recent years, the hydrothermal synthesis method has attracted attention as a soft chemistry process that can be synthesized under higher temperature conditions by conventional solid-phase synthesis methods under milder temperature conditions. As an attempt to crystallize anatase from amorphous titanium oxide using hydrothermal reaction, an example using amorphous titanium oxide obtained by hydrolyzing titanium tetraethoxide as a starting material has been reported. I have. It has been revealed that crystallization to anatase proceeds at 400 ° C. or higher in a heating atmosphere containing no water, whereas crystallization to anatase occurs at 250 ° C. under a steam pressure of 98 kPa. Also, under hydrothermal conditions where a large amount of water at 250 ° C. exists, many anatase crystal nuclei are generated,
Since each crystal nucleus cannot grow large, 11 nm
It is reported that crystals of the order of magnitude are produced (High Pressure Symposium Proceedings, P320, pp117 (1995)). However, detailed hydrothermal temperature conditions and the photocatalytic activity of the obtained anatase crystal have not been studied.
【０００４】このほか出発物質としてチタニウムテトラ
エトキシドを加水分解して得られた非晶質酸化チタンを
用い、高温溶媒中での結晶化に及ぼす溶媒効果も検討さ
れており、高温水中ではメタノール及びヘキサンに比
べ、結晶化が容易に進行することが報告されている（Ｍ
ＲＳ予稿集、ｐｐ５１０（１９９７））が、高温水中で
結晶化させたアナタースは他の溶媒中で結晶化させたも
のより光触媒活性が低下することが報告されている。こ
の場合も原料であるチタニウムテトラエトキシドを加水
分解した後、固液分離、洗浄、乾燥させた非晶質酸化チ
タンを高温溶媒中で加熱処理するため、合成操作が煩雑
になるという欠点がある。In addition, an amorphous titanium oxide obtained by hydrolyzing titanium tetraethoxide is used as a starting material, and the effect of a solvent on crystallization in a high-temperature solvent has been studied. It has been reported that crystallization proceeds more easily than hexane (M
RS Proceedings, pp 510 (1997)) report that anatase crystallized in high-temperature water has lower photocatalytic activity than that crystallized in other solvents. In this case as well, after the titanium tetraethoxide as a raw material is hydrolyzed, solid-liquid separation, washing, and heat treatment of the dried amorphous titanium oxide in a high-temperature solvent are disadvantageous in that the synthesis operation becomes complicated. .
【０００５】[0005]
【発明が解決しようとする課題】本発明は、このような
従来の酸化チタン光触媒がもつ欠点を克服し、光触媒活
性に優れ、かつ簡単な操作で容易に製造しうる経済的に
有利な酸化チタン光触媒を提供することを目的としてな
されたものである。SUMMARY OF THE INVENTION The present invention overcomes the disadvantages of the conventional titanium oxide photocatalysts, has excellent photocatalytic activity, and is economically advantageous because it can be easily produced by a simple operation. The purpose of the present invention is to provide a photocatalyst.
【０００６】[0006]
【課題を解決するための手段】本発明者らは、光触媒と
して有用な酸化チタンについて鋭意研究を重ねた結果、
チタニウムテトラアルコキシドを水と反応させ、酸化チ
タンの加水分解物を生成させ、そのまま母液とともに水
熱条件下で加熱処理させることにより光触媒活性に優れ
たアナタース型酸化チタンが得られることを見い出し、
この知見に基づいて本発明を完成するに至った。The present inventors have conducted intensive studies on titanium oxide useful as a photocatalyst.
Reacting titanium tetraalkoxide with water, producing a hydrolyzate of titanium oxide, and finding that an anatase-type titanium oxide excellent in photocatalytic activity can be obtained by performing heat treatment under hydrothermal conditions together with the mother liquor,
Based on this finding, the present invention has been completed.
【０００７】上記課題を解決する本発明は、以下の技術
的手段から構成される。 （１）基本構造が、一般式 ＴｉＯ2 ・ｘＨ2 Ｏ・ｙＰｔ （式中のｘは０〜１. ５の数、ｙは０より大きく０. ０
５未満の数である）で表される酸化チタン光触媒。 （２）担体である酸化チタンの結晶構造がアナタースで
あることを特徴とする前記（１）記載の酸化チタン光触
媒。 （３）チタニウムテトラアルコキシドを水と混合して、
沈殿物を生成させ、水熱条件下で処理して得られた反応
生成物をろ過・水洗し、必要に応じて乾燥した後、白金
含有溶液に浸漬し、紫外光を照射することを特徴とする
基本構造が、一般式 ＴｉＯ2 ・ｘＨ2 Ｏ・ｙＰｔ （式中のｘは０〜１. ５の数、ｙは０より大きく０. ０
５未満の数である）で表される酸化チタン光触媒の製造
方法。 （４）チタニウムテトラアルコキシドを水と混合して、
沈殿物を生成させ、水熱条件下で処理して得られた反応
生成物をろ過・水洗し、必要に応じて乾燥した後、白金
含有溶液に浸漬し、紫外光を照射することを特徴とする
担体である酸化チタンの結晶構造がアナタースである前
記（３）記載の酸化チタン光触媒の製造方法。 （５）チタニウムテトラアルコキシドとして、エトキシ
ド、プロポキシド、ブトキシドを原料として使用するこ
とを特徴とする前記（３）又は（４）記載の酸化チタン
光触媒の製造方法。 （６）水熱処理温度が１００℃以上であることを特徴と
する前記（３）、（４）又は（５）記載の酸化チタン光
触媒の製造方法。 （７）水熱処理時間が６時間以上であることを特徴とす
る前記（３）、（４）、（５）又は（６）記載の酸化チ
タン光触媒の製造方法。[0007] The present invention for solving the above problems comprises the following technical means. (1) The basic structure is represented by the general formula TiO 2 .xH 2 O.yPt (where x is a number from 0 to 1.5, and y is greater than 0 and 0.0
A titanium oxide photocatalyst represented by the formula: (2) The titanium oxide photocatalyst according to the above (1), wherein the crystal structure of the titanium oxide as a carrier is anatase. (3) mixing titanium tetraalkoxide with water;
A precipitate is formed, and the reaction product obtained by treatment under hydrothermal conditions is filtered, washed with water, dried if necessary, immersed in a platinum-containing solution, and irradiated with ultraviolet light. Is represented by the general formula: TiO 2 .xH 2 O.yPt (where x is a number from 0 to 1.5, and y is greater than 0 and 0.0
The number is less than 5). (4) mixing titanium tetraalkoxide with water;
A precipitate is formed, and the reaction product obtained by treatment under hydrothermal conditions is filtered, washed with water, dried if necessary, immersed in a platinum-containing solution, and irradiated with ultraviolet light. The method for producing a titanium oxide photocatalyst according to the above (3), wherein the crystal structure of the titanium oxide as the carrier to be converted is anatase. (5) The method for producing a titanium oxide photocatalyst according to the above (3) or (4), wherein ethoxide, propoxide, or butoxide is used as a raw material as the titanium tetraalkoxide. (6) The method for producing a titanium oxide photocatalyst according to the above (3), (4) or (5), wherein the hydrothermal treatment temperature is 100 ° C. or higher. (7) The method for producing a titanium oxide photocatalyst according to the above (3), (4), (5) or (6), wherein the hydrothermal treatment time is 6 hours or more.
【０００８】すなわち、本発明は、基本構造が、一般式 ＴｉＯ2 ・ｘＨ2 Ｏ・ｙＰｔ （式中のｘは０〜１. ５の数、ｙは０より大きく０. ０
５未満の数である）で表される酸化チタン光触媒を提供
するものである。本発明によれば、前記チタン酸化物光
触媒はチタニウムテトラアルコキシドと水溶液とから沈
殿物を生成させ、それを母液とともに水熱処理し、得ら
れたスラリーをろ別、水洗後、乾燥させ、次いで、得ら
れた酸化チタンを塩化白金酸溶液とともに高圧水銀ラン
プ照射下で反応させることにより製造することができ
る。ここで、白金酸は助触媒である白金の原料であり、
塩化白金酸水溶液に酸化チタンを懸濁させて光を照射す
ると、光励起により生じた電子が塩化白金酸イオンを還
元して酸化チタン上に白金の微粒子を析出させるもので
ある。この反応は、白色の酸化チタン粉末が次第に灰色
に変化することにより確認できる。That is, in the present invention, the basic structure is represented by the general formula TiO 2 .xH 2 O.yPt (where x is a number of 0 to 1.5, and y is greater than 0 and 0.0
(The number is less than 5). According to the present invention, the titanium oxide photocatalyst generates a precipitate from the titanium tetraalkoxide and the aqueous solution, which is subjected to hydrothermal treatment together with the mother liquor, and the obtained slurry is filtered, washed with water, dried, and then obtained. It can be produced by reacting the obtained titanium oxide with a chloroplatinic acid solution under irradiation with a high-pressure mercury lamp. Here, platinic acid is a raw material of platinum as a co-catalyst,
When titanium oxide is suspended in an aqueous chloroplatinic acid solution and irradiated with light, electrons generated by photoexcitation reduce chloroplatinate ions to precipitate fine platinum particles on the titanium oxide. This reaction can be confirmed by the white titanium oxide powder gradually changing to gray.
【０００９】[0009]
【発明の実施の形態】次に、本発明についてさらに詳細
に説明する。本発明の酸化チタン光触媒は、一般式 ＴｉＯ2 ・ｘＨ2 Ｏ・ｙＰｔ で表される基本構造を有するものである。一般式におい
てｘは０〜１. ５の数、ｙは０より大きく０. ０５未満
の数である。このような基本構造を有する複合化合物は
良好な光触媒活性を有している。Next, the present invention will be described in more detail. The titanium oxide photocatalyst of the present invention has a basic structure represented by the general formula TiO 2 .xH 2 O.yPt. In the general formula, x is a number from 0 to 1.5, and y is a number greater than 0 and less than 0.05. A composite compound having such a basic structure has good photocatalytic activity.
【００１０】このような酸化チタン光触媒は、（１）チ
タン酸化物の生成工程、及び（２）白金担持工程を順次
施すことによって製造することができる。[0010] Such a titanium oxide photocatalyst can be produced by sequentially performing (1) a step of forming a titanium oxide and (2) a step of supporting platinum.
【００１１】前記（１）の酸化チタンの生成工程におい
ては、チタニウムテトラアルコキシドに水熱処理工程を
施すことにより酸化チタンを製造することができる。水
の添加量はチタニウムテトラアルコキシドの加水分解に
必要な化学両論量以上とする。次にチタニウムテトラア
ルコキシド溶液を用意する。このチタニウムテトラアル
コキシドとしては、エトキシド、プロポキシド、ブトキ
シドなどを挙げることができる。In the step (1) of forming titanium oxide, titanium oxide can be produced by subjecting titanium tetraalkoxide to a hydrothermal treatment step. The amount of water to be added is not less than the stoichiometric amount necessary for hydrolysis of titanium tetraalkoxide. Next, a titanium tetraalkoxide solution is prepared. Examples of the titanium tetraalkoxide include ethoxide, propoxide, butoxide and the like.
【００１２】水溶液にチタニウムテトラアルコキシド溶
液を滴下させ、沈殿物を生成させる。チタン酸アルコキ
シド溶液に水溶液を滴下しても沈殿物は得られる。混合
するチタニウムテトラアルコキシド量は水に対するモル
比として１００％以下好ましくは１０％以下の値が用い
られる。得られた沈殿物は母液とともに例えばテフロン
内筒型反応容器、ガラスアンプル、オートクレーブなど
の密封容器を用い、水熱処理を行うことができる。好適
には、処理物はろ別、水洗により副生溶解質を除去する
が、この場合、ろ別、水洗と同等の固液分離、洗浄方法
であれば、適宜の方法を同様に使用することができる。
白金担持工程に供する沈殿物は特に乾燥する必要はない
が、必要に応じて乾燥してから用いても良い。The titanium tetraalkoxide solution is dropped into the aqueous solution to form a precipitate. Even if the aqueous solution is dropped into the alkoxide titanate solution, a precipitate can be obtained. The amount of titanium tetraalkoxide to be mixed is 100% or less, preferably 10% or less as a molar ratio to water. The obtained precipitate can be subjected to hydrothermal treatment together with the mother liquor using a sealed container such as a Teflon inner cylinder type reaction vessel, a glass ampule, an autoclave, or the like. Preferably, the treated product is filtered to remove by-product solutes by washing with water. In this case, if a solid-liquid separation and washing method equivalent to that of filtration, washing with water is used, an appropriate method may be used in the same manner. it can.
The precipitate to be subjected to the platinum loading step does not need to be particularly dried, but may be used after drying if necessary.
【００１３】次に、前記（２）の白金担持工程において
は、まず白金含有溶液を調製する。白金含有溶液の濃度
は複合体の担持量に応じて任意に調整できるが、（１）
の工程で得られた沈殿物の重量に対し、０. １〜１０ｗ
ｔ％、好ましくは１〜３ｗｔ％の範囲に入るように調製
する。例えば、２ｗｔ％の白金を担持すれば基本式のｙ
の値は０. ００８程度の値となる。この溶液を室温で、
沈殿物を加え、１〜２４時間好ましくは３〜１０時間、
４００Ｗ高圧水銀ランプを用いた内部照射反応管中で撹
拌する。反応後の生成物はろ別、水洗し、エタノールで
洗浄後、乾燥させる。乾燥には一般的な乾燥機や乾燥剤
の入ったデシケータを用い、例えば室温ないし５０℃で
乾燥する。また、スプレードライ方式あるいは凍結乾燥
方式によっても乾燥できる。得られた生成物は微細な粒
状の形態を示す。乾燥前に任意の形状に成形した後、乾
燥しても良い。Next, in the platinum loading step (2), a platinum-containing solution is first prepared. The concentration of the platinum-containing solution can be arbitrarily adjusted in accordance with the amount of the complex to be carried.
0.1 to 10 w with respect to the weight of the precipitate obtained in the step
t%, preferably in the range of 1 to 3 wt%. For example, if 2 wt% of platinum is supported, y in the basic formula
Is about 0.008. At room temperature,
Add the precipitate, 1-24 hours, preferably 3-10 hours,
Stir in an internal irradiation reaction tube using a 400 W high pressure mercury lamp. The product after the reaction is separated by filtration, washed with water, washed with ethanol and dried. For drying, a general dryer or a desiccator containing a desiccant is used, for example, at room temperature to 50 ° C. Further, it can be dried by a spray drying method or a freeze drying method. The product obtained shows a fine granular morphology. After being formed into an arbitrary shape before drying, it may be dried.
【００１４】このようにして得られた酸化チタン光触媒
は化学分析、Ｘ線回折、熱分析、赤外分光、走査型電子
顕微鏡などの測定などによって確認できる。例えば、熱
分析により６０℃付近にピークを有するDTA 吸熱ピーク
に相当する吸着水の熱天秤の減量からＸ値を得ることが
できる。また、光触媒活性は例えばメタノールを含む水
の光分解による水素ガス発生速度を調べることにより評
価することができる。通常、酸化チタンの水素発生電位
は水の還元電位に近いことから、水素の発生速度は著し
く遅い。そこで、白金などの助触媒を担持するととも
に、還元反応を促進する試薬を導入することにより、活
性を高めることが必要であり、メタノールは還元反応の
犠牲剤として働く。The titanium oxide photocatalyst thus obtained can be confirmed by chemical analysis, X-ray diffraction, thermal analysis, infrared spectroscopy, measurement with a scanning electron microscope or the like. For example, the X value can be obtained from the weight loss of the thermobalance of the adsorbed water corresponding to the DTA endothermic peak having a peak near 60 ° C. by thermal analysis. The photocatalytic activity can be evaluated, for example, by examining the rate of hydrogen gas generation by photolysis of water containing methanol. Normally, the hydrogen generation potential of titanium oxide is close to the reduction potential of water, so the hydrogen generation rate is extremely low. Therefore, it is necessary to increase the activity by supporting a promoter such as platinum and introducing a reagent that promotes the reduction reaction, and methanol acts as a sacrificial agent for the reduction reaction.
【００１５】本発明の酸化チタン光触媒の生成は、例え
ばＸ線回折測定により容易に確認することができる。銅
管球、ニッケルフィルターを使用して測定した場合、
（１）の工程で得られた沈殿物は２θ＝２５. ３°、３
７. ８°、４８. １°、５３.９°、５５. １°及び６
２. ７°にそれぞれアナタースの（１０１）、（００
４）、（２００）、（１０５）、（２１１）及び（２０
４）回折線に対応するピークが認められるが、処理温
度、時間などの合成条件により回折線ピーク強度が変化
する。（１０１）回折線の半価幅から結晶子の大きさを
見積もることができる。本発明の酸化チタン光触媒の形
態は走査型電子顕微鏡によって微細な粒子の凝集体とし
て観察されうる。The production of the titanium oxide photocatalyst of the present invention can be easily confirmed by, for example, X-ray diffraction measurement. When measured using a copper tube and a nickel filter,
The precipitate obtained in the step (1) is 2θ = 25.3 °, 3
7.8 °, 48.1 °, 53.9 °, 55.1 ° and 6
At 2.7 °, the anatase (101) and (00)
4), (200), (105), (211) and (20)
4) A peak corresponding to the diffraction line is observed, but the diffraction line peak intensity changes depending on the synthesis conditions such as the processing temperature and time. (101) The crystallite size can be estimated from the half width of the diffraction line. The form of the titanium oxide photocatalyst of the present invention can be observed as an aggregate of fine particles by a scanning electron microscope.
【００１６】[0016]
【実施例】次に実施例により本発明をさらに詳細に説明
するが、本発明は、これらの例によってなんら限定され
るものではない。Next, the present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.
【００１７】比較例１ ４ｍｌのチタニウムテトライソプロポキシドを蒸留水２
０ｍｌに加え、３時間撹拌し、そのままの状態で熟成さ
せた後、沈殿物をろ別、水洗後、乾燥させて比較例製品
１を１ｇ得た。比較例製品１のＸ線回折結果ではアモル
ファスなＸ線回折像が認められた。Comparative Example 1 4 ml of titanium tetraisopropoxide was added to distilled water 2
After 0 hours, the mixture was stirred for 3 hours and aged as it was. The precipitate was separated by filtration, washed with water, and dried to obtain 1 g of product of Comparative Example 1. An X-ray diffraction image of the product of Comparative Example 1 showed an amorphous X-ray diffraction image.
【００１８】実施例１ 耐圧テフロン製容器に４ｍｌのチタニウムテトライソプ
ロポキシドと蒸留水２０ｍｌを加え、密封した後、２０
分間振蕩機を用い、振り混ぜた。耐圧テフロン製容器を
恒温槽あるいは、電気炉に入れ、１００℃において２４
時間保持した。耐圧テフロン製容器を取り出し、放冷
後、沈殿物をろ別、水洗、乾燥させた。次に内部照射型
光化学反応容器に２×１０-4Ｍ白金酸溶液５００ｍｌと
前記沈殿物１ｇを添加し、室温で約５時間４００Ｗ高圧
水銀ランプを用い照射させた。白金酸は白金担持量とし
て２ｗｔ％に想定して反応させたものである（ｙ＝０.
００８に相当する）。反応生成物はろ別、水洗、エタノ
ールで洗浄した後、デシケータを用い室温で乾燥させ、
本発明製品１を得た。得られた本発明製品のＸ線回折結
果では、アナタース型酸化チタンの（１０１）、（００
４）、（２００）、（１０５）、（２１１）及び（２０
４）に相当すると考えられる２θ＝２５. ３°、３７.
８°、４８. １°、５３. ９°、５５. １°及び６２.
７°にブロードなピークが認められた。（１０１）回折
線の半価幅から求めた結晶子径は１９.７ｎｍであっ
た。比表面積は１８２ｍ2 ｇ-1であった。熱重量減量値
から求めたｘの値は１. ０８であり、ｙの値は０. ００
８であった。Example 1 4 ml of titanium tetraisopropoxide and 20 ml of distilled water were added to a pressure-resistant Teflon container, and the container was sealed.
Shake using a shaker for minutes. Place the pressure-resistant Teflon container in a thermostat or an electric furnace,
Hold for hours. The pressure-resistant Teflon container was taken out, allowed to cool, and the precipitate was separated by filtration, washed with water, and dried. Next, 500 ml of a 2 × 10 −4 M platinic acid solution and 1 g of the precipitate were added to an internal irradiation type photochemical reaction vessel, and irradiation was performed at room temperature for about 5 hours using a 400 W high pressure mercury lamp. Platinic acid was reacted on the assumption that the amount of platinum carried was 2 wt% (y = 0.
008). The reaction product is separated by filtration, washed with water, washed with ethanol, and then dried at room temperature using a desiccator.
Inventive product 1 was obtained. According to the X-ray diffraction results of the obtained product of the present invention, (101), (00)
4), (200), (105), (211) and (20)
2θ = 25.3 °, which is considered to correspond to 4), 37.
8 °, 48.1 °, 53.9 °, 55.1 ° and 62.
A broad peak was observed at 7 °. (101) The crystallite diameter determined from the half width of the diffraction line was 19.7 nm. The specific surface area was 182 m 2 g −1 . The value of x obtained from the thermogravimetric weight loss value is 1.08, and the value of y is 0.00
It was 8.
【００１９】実施例２ 水熱反応温度を１５０℃とした以外は実施例１に従って
本発明製品２を得た。本発明製品のＸ線回折結果では、
アナタース型酸化チタンの（１０１）、（００４）、
（２００）、（１０５）、（２１１）及び（２０４）に
相当すると考えられる２θ＝２５. ３°、３７. ８°、
４８. １°、５３. ９°、５５. １°及び６２. ７°に
ブロードなピークが認められた。（１０１）回折線の半
価幅から求めた結晶子径は２３. ０ｎｍであった。比表
面積は１６２ｍ2 ｇ-1であった。熱重量減量値から求め
たｘの値は０. ７７であり、ｙの値は０. ００７であっ
た。Example 2 A product 2 of the present invention was obtained according to Example 1 except that the hydrothermal reaction temperature was changed to 150 ° C. According to the X-ray diffraction results of the product of the present invention,
(101), (004) of anatase type titanium oxide,
2θ = 25.3 °, 37.8 °, which are considered to correspond to (200), (105), (211) and (204),
Broad peaks were observed at 48.1 °, 53.9 °, 55.1 ° and 62.7 °. (101) The crystallite diameter determined from the half width of the diffraction line was 23.0 nm. The specific surface area was 162 m 2 g −1 . The value of x obtained from the thermogravimetric loss value was 0.77, and the value of y was 0.007.
【００２０】実施例３ 水熱反応温度を２００℃とした以外は実施例１に従って
本発明製品３を得た。本発明製品のＸ線回折結果では、
得られた本発明製品のＸ線回折結果では、アナタース型
酸化チタンの（１０１）、（００４）、（２００）、
（１０５）、（２１１）及び（２０４）に相当すると考
えられる２θ＝２５. ３°、３７. ８°、４８. １°、
５３. ９°、５５. １°及び６２. ７°にブロードなピ
ークが認められた。（１０１）回折線の半価幅から求め
た結晶子径は２７. ６ｎｍであった。比表面積は１２９
ｍ2 ｇ-1であった。熱重量減量値から求めたｘの値は
０. ５１であり、ｙの値は０. ００８であった。Example 3 A product 3 of the present invention was obtained according to Example 1 except that the hydrothermal reaction temperature was changed to 200 ° C. According to the X-ray diffraction results of the product of the present invention,
According to the X-ray diffraction results of the obtained product of the present invention, (101), (004), (200),
2105 = 25.3 °, 37.8 °, 48.1 °, which are considered to correspond to (105), (211) and (204),
Broad peaks were observed at 53.9 °, 55.1 ° and 62.7 °. (101) The crystallite diameter determined from the half width of the diffraction line was 27.6 nm. The specific surface area is 129
m 2 g −1 . The value of x obtained from the thermogravimetric weight loss value was 0.51 and the value of y was 0.008.
【００２１】実施例４ 水熱反応温度を２５０℃とした以外は実施例１に従って
本発明製品４を得た。本発明製品のＸ線回折結果では、
得られた本発明製品のＸ線回折結果では、アナタース型
酸化チタンの（１０１）、（００４）、（２００）、
（１０５）、（２１１）及び（２０４）に相当すると考
えられる２θ＝２５. ３°、３７. ８°、４８. １°、
５３. ９°、５５. １°及び６２. ７°にブロードなピ
ークが認められた。（１０１）回折線の半価幅から求め
た結晶子径は３４. ５ｎｍであった。比表面積は１１７
ｍ2 ｇ-1であった。熱重量減量値から求めたｘの値は
０. ３９であり、ｙの値は０. ００７であった。Example 4 A product 4 of the present invention was obtained according to Example 1 except that the hydrothermal reaction temperature was changed to 250 ° C. According to the X-ray diffraction results of the product of the present invention,
According to the X-ray diffraction results of the obtained product of the present invention, (101), (004), (200),
2105 = 25.3 °, 37.8 °, 48.1 °, which are considered to correspond to (105), (211) and (204),
Broad peaks were observed at 53.9 °, 55.1 ° and 62.7 °. (101) The crystallite diameter determined from the half width of the diffraction line was 34.5 nm. Specific surface area is 117
m 2 g −1 . The value of x obtained from the thermogravimetric weight loss value was 0.39, and the value of y was 0.007.
【００２２】実施例５ 水熱反応温度を３００℃とした以外は実施例１に従って
本発明製品５を得た。本発明製品のＸ線回折結果では、
得られた本発明製品のＸ線回折結果では、アナタース型
酸化チタンの（１０１）、（００４）、（２００）、
（１０５）、（２１１）及び（２０４）に相当すると考
えられる２θ＝２５. ３°、３７. ８°、４８. １°、
５３. ９°、５５. １°及び６２. ７°にシャープなピ
ークが認められた。（１０１）回折線の半価幅から求め
た結晶子径は９２. １ｎｍであった。比表面積は４１ｍ
2 ｇ-1であった。熱重量減量値から求めたｘの値は０.
１６であり、ｙの値は０. ００７であった。Example 5 A product 5 of the present invention was obtained according to Example 1 except that the hydrothermal reaction temperature was changed to 300 ° C. According to the X-ray diffraction results of the product of the present invention,
According to the X-ray diffraction results of the obtained product of the present invention, (101), (004), (200),
2105 = 25.3 °, 37.8 °, 48.1 °, which are considered to correspond to (105), (211) and (204),
Sharp peaks were observed at 53.9 °, 55.1 ° and 62.7 °. (101) The crystallite diameter determined from the half width of the diffraction line was 92.1 nm. Specific surface area is 41m
It was 2 g -1 . The value of x obtained from the thermogravimetric weight loss value was 0.3.
16, and the value of y was 0.007.
【００２３】実施例６ 水熱反応温度を４００℃とした以外は実施例１に従って
本発明製品６を得た。反応終了時の平衡ｐＨは６．８で
あった。本発明製品のＸ線回折結果では、得られた本発
明製品のＸ線回折結果では、アナタース型酸化チタンの
（１０１）、（００４）、（２００）、（１０５）、
（２１１）及び（２０４）に相当すると考えられる２θ
＝２５. ３°、３７. ８°、４８. １°、５３. ９°、
５５. １°及び６２. ７°にシャープなピークが認めら
れた。（１０１）回折線の半価幅から求めた結晶子径は
１１５. ０ｎｍであった。比表面積は６ｍ2 ｇ-1であっ
た。熱重量減量値から求めたｘの値は０. １４であり、
ｙの値は０. ００８であった。Example 6 A product 6 of the present invention was obtained according to Example 1 except that the hydrothermal reaction temperature was changed to 400 ° C. The equilibrium pH at the end of the reaction was 6.8. According to the X-ray diffraction results of the product of the present invention, the X-ray diffraction results of the obtained product of the present invention show that the anatase-type titanium oxides (101), (004), (200), (105),
2θ considered to correspond to (211) and (204)
= 25.3 °, 37.8 °, 48.1 °, 53.9 °,
Sharp peaks were observed at 55.1 ° and 62.7 °. (101) The crystallite diameter determined from the half width of the diffraction line was 115.0 nm. The specific surface area was 6 m 2 g −1 . The value of x obtained from the thermogravimetric weight loss value was 0.14,
The value of y was 0.008.
【００２４】比較例２ 市販の酸化チタンについて白金担持製品を調製した。比
較例酸化チタン２〜４は和光純薬（株）の試薬であり、
それぞれ、アモルファス型、ルチル型、アナタース／ル
チル混合型酸化チタンである。比較例酸化チタン５はメ
ルクの酸化チタンで結晶型はアナタース型である。内部
照射型光化学反応容器に蒸留水５００ml及び０. ０２Ｍ
白金酸溶液５ｍｌを加え、さらに前記比較例酸化チタン
１ｇを懸濁させ、室温で約５時間４００Ｗ高圧水銀ラン
プを用い照射させた。白金酸は白金担持量として２ｗｔ
％（ｙ＝０. ００８）に想定して反応させたものであ
る。反応生成物はろ別、水洗、エタノールで洗浄した
後、デシケータを用い室温で乾燥させ、比較例製品２〜
５を得た。Comparative Example 2 A platinum-supported product was prepared from commercially available titanium oxide. Comparative Examples Titanium oxides 2 to 4 are reagents of Wako Pure Chemical Industries, Ltd.
They are amorphous type, rutile type, and anatase / rutile mixed type titanium oxide, respectively. Comparative Example Titanium oxide 5 is Merck's titanium oxide, and the crystal type is an anatase type. 500 ml of distilled water and 0.02M in an internal irradiation type photochemical reaction vessel
5 ml of a platinic acid solution was added, and 1 g of the titanium oxide of the comparative example was suspended, and irradiated with a 400 W high-pressure mercury lamp at room temperature for about 5 hours. Platinic acid is 2 wt.
% (Y = 0.008). The reaction product was separated by filtration, washed with water, washed with ethanol, and then dried at room temperature using a desiccator.
5 was obtained.
【００２５】実施例７ 得られた本発明製品１〜６及び比較例製品１〜５を用い
て水素ガス発生速度を反応温度３０℃で測定した。各製
品０．３g とメタノール水溶液（メタノール：水＝１：
３体積比）６００ｍｌをパイレックス製内部照射型光化
学反応容器に加え、３０℃の恒温槽中で高圧水銀ランプ
を用い、紫外線を照射した。発生ガス量をガスビュレッ
トにより経時変化を測定し、また、照射中止後にガス組
成をガスクロマトグラフィにより求め、水素ガス発生速
度を算出した。（その結果を表１に示す。）Example 7 Using the obtained products 1 to 6 of the present invention and comparative products 1 to 5, the rate of hydrogen gas generation was measured at a reaction temperature of 30 ° C. 0.3 g of each product and methanol aqueous solution (methanol: water = 1:
600 ml (3 volume ratio) was added to a Pyrex internal irradiation type photochemical reaction vessel, and ultraviolet rays were irradiated using a high-pressure mercury lamp in a thermostat at 30 ° C. The amount of generated gas was measured over time using a gas burette, and after the irradiation was stopped, the gas composition was determined by gas chromatography to calculate the hydrogen gas generation rate. (The results are shown in Table 1.)
【００２６】[0026]
【表１】 [Table 1]
【００２７】水熱処理を施さない比較例製品１は著しく
低い水素発生速度を示す。これに対し、水熱処理を行っ
た本発明製品は、水熱温度の増加とともに水素発生速度
は２００℃まで増加し、最大４００ｍｌ／ｈの値を示し
た。さらに水熱温度を高くすると水素発生速度は低下す
る傾向が認められるが、４００℃水熱処理物でも２００
ｍｌ／ｈを越える値を有している。水熱処理温度が１０
０〜２００℃という比較的穏和な条件下で合成したもの
に高い水素発生速度が認められることから、経済的であ
り、また、高圧に伴う危険も少なくなり有利と考えられ
る。市販の酸化チタンに白金を担持させた比較例製品２
〜５はメタノール水溶液からの水素発生速度は１００ｍ
ｌ／ｈ前後の値を示し、活性はそれほど高くないことに
加え、反応時間の経過とともに水素発生速度の低下が認
められるものもあった。一方、本発明の光触媒はこれら
の比較例製品３〜５に比べ、２〜４倍の高い水素ガス発
生速度を有することに加え、反応時間の経過に伴う水素
ガス発生速度の低下も見られず、２００ｍｌ／ｈ以上の
値を保持し、高い光触媒活性を有しており、水の光分解
触媒として有用である。Comparative Product 1 without hydrothermal treatment shows a significantly lower rate of hydrogen evolution. On the other hand, in the product of the present invention subjected to the hydrothermal treatment, the hydrogen generation rate increased to 200 ° C. as the hydrothermal temperature increased, and showed a value of 400 ml / h at the maximum. When the hydrothermal temperature is further increased, the hydrogen generation rate tends to decrease.
It has a value exceeding ml / h. Hydrothermal treatment temperature is 10
Since a high rate of hydrogen generation is observed in a product synthesized under a relatively mild condition of 0 to 200 ° C., it is economical, and it is considered to be advantageous because the danger associated with high pressure is reduced. Comparative product 2 with platinum supported on commercially available titanium oxide
No. 5 is 100 m hydrogen generation rate from methanol aqueous solution
The value was around 1 / h, and the activity was not so high, and in some cases, the hydrogen generation rate decreased with the passage of reaction time. On the other hand, the photocatalyst of the present invention has a hydrogen gas generation rate that is 2 to 4 times higher than those of the comparative examples 3 to 5, and the hydrogen gas generation rate does not decrease with the lapse of reaction time. , And has a high photocatalytic activity, and is useful as a water photolysis catalyst.
【００２８】実施例８ 実施例３において、水熱反応時間を６時間とした以外は
実施例３と同様な操作により本発明製品８を得た。本発
明製品のＸ線回折結果では、得られた本発明製品のＸ線
回折結果では、アナタース型酸化チタンの（１０１）、
（００４）、（２００）、（１０５）、（２１１）及び
（２０４）に相当すると考えられる２θ＝２５. ３°、
３７. ８°、４８. １°、５３. ９°、５５. １°及び
６２. ７°にブロードなピークが認められた。（１０
１）回折線の半価幅から求めた結晶子径は２５. １ｎｍ
であった。熱重量減量値から求めたｘの値は１. ３３で
あり、ｙの値は０. ００８であった。Example 8 A product 8 of the present invention was obtained in the same manner as in Example 3, except that the hydrothermal reaction time was changed to 6 hours. According to the X-ray diffraction result of the product of the present invention, the X-ray diffraction result of the obtained product of the present invention shows that the anatase-type titanium oxide (101),
2θ = 25.3 ° considered to correspond to (004), (200), (105), (211) and (204);
Broad peaks were observed at 37.8 °, 48.1 °, 53.9 °, 55.1 ° and 62.7 °. (10
1) The crystallite diameter determined from the half width of the diffraction line is 25.1 nm.
Met. The value of x obtained from the thermogravimetric weight loss value was 1.33, and the value of y was 0.008.
【００２９】実施例９ 実施例３において、水熱反応時間を１２時間とした以外
は実施例３と同様な操作により１ｇの本発明製品９を得
た。本発明製品のＸ線回折結果では、得られた本発明製
品のＸ線回折結果では、アナタース型酸化チタンの（１
０１）、（００４）、（２００）、（１０５）、（２１
１）及び（２０４）に相当すると考えられる２θ＝２
５. ３°、３７. ８°、４８. １°、５３. ９°、５
５. １°及び６２. ７°にブロードなピークが認められ
た。（１０１）回折線の半価幅から求めた結晶子径は２
７. ６ｎｍであった。熱重量減量値から求めたｘの値は
０. ５２であり、ｙの値は０. ００８であった。Example 9 1 g of the product 9 of the present invention was obtained in the same manner as in Example 3, except that the hydrothermal reaction time was changed to 12 hours. According to the X-ray diffraction result of the product of the present invention, the X-ray diffraction result of the obtained product of the present invention shows that (1)
01), (004), (200), (105), (21)
2θ = 2 considered to correspond to 1) and (204)
5.3 °, 37.8 °, 48.1 °, 53.9 °, 5
Broad peaks were observed at 5.1 ° and 62.7 °. (101) The crystallite diameter determined from the half width of the diffraction line is 2
It was 7.6 nm. The value of x obtained from the thermogravimetric weight loss value was 0.52, and the value of y was 0.008.
【００３０】実施例１０ 実施例３において、水熱反応時間を１８時間とした以外
は実施例３と同様な操作により１ｇの本発明製品１０を
得た。本発明製品のＸ線回折結果では、得られた本発明
製品のＸ線回折結果では、アナタース型酸化チタンの
（１０１）、（００４）、（２００）、（１０５）、
（２１１）及び（２０４）に相当すると考えられる２θ
＝２５. ３°、３７. ８°、４８. １°、５３. ９°、
５５. １°及び６２. ７°にブロードなピークが認めら
れた。（１０１）回折線の半価幅から求めた結晶子径は
３０. ７ｎｍであった。熱重量減量値から求めたｘの値
は０.８０であり、ｙの値は０. ００８であった。Example 10 1 g of the product 10 of the present invention was obtained in the same manner as in Example 3 except that the hydrothermal reaction time was changed to 18 hours. According to the X-ray diffraction results of the product of the present invention, the X-ray diffraction results of the obtained product of the present invention show that the anatase-type titanium oxides (101), (004), (200), (105),
2θ considered to correspond to (211) and (204)
= 25.3 °, 37.8 °, 48.1 °, 53.9 °,
Broad peaks were observed at 55.1 ° and 62.7 °. (101) The crystallite diameter determined from the half width of the diffraction line was 30.7 nm. The value of x obtained from the thermogravimetric weight loss value was 0.80, and the value of y was 0.008.
【００３１】実施例１１ 実施例３において、水熱反応時間を４８時間とした以外
は実施例３と同様な操作により１ｇの本発明製品１１を
得た。本発明製品のＸ線回折結果では、得られた本発明
製品のＸ線回折結果では、アナタース型酸化チタンの
（１０１）、（００４）、（２００）、（１０５）、
（２１１）及び（２０４）に相当すると考えられる２θ
＝２５. ３°、３７. ８°、４８. １°、５３. ９°、
５５. １°及び６２. ７°にブロードなピークが認めら
れた。（１０１）回折線の半価幅から求めた結晶子径は
３９. ５ｎｍであった。熱重量減量値から求めたｘの値
は０.４０であり、ｙの値は０. ００８であった。Example 11 1 g of the product 11 of the present invention was obtained in the same manner as in Example 3, except that the hydrothermal reaction time was changed to 48 hours. According to the X-ray diffraction results of the product of the present invention, the X-ray diffraction results of the obtained product of the present invention show that the anatase-type titanium oxides (101), (004), (200), (105),
2θ considered to correspond to (211) and (204)
= 25.3 °, 37.8 °, 48.1 °, 53.9 °,
Broad peaks were observed at 55.1 ° and 62.7 °. (101) The crystallite diameter determined from the half width of the diffraction line was 39.5 nm. The value of x obtained from the thermogravimetric weight loss value was 0.40, and the value of y was 0.008.
【００３２】実施例１２ 水素発生速度が最も大きかった水熱合成温度２００℃に
ついて反応時間を６時間から４８時間まで変えて合成を
行った実施例３及び８〜１１の本発明製品について光触
媒活性を評価した。（その結果を表２に示す。）Example 12 The photocatalytic activities of the products of the present invention of Examples 3 and 8 to 11 in which the reaction time was changed from 6 hours to 48 hours at a hydrothermal synthesis temperature of 200 ° C. at which the rate of hydrogen evolution was the largest were performed. evaluated. (The results are shown in Table 2.)
【００３３】[0033]
【表２】 [Table 2]
【００３４】水熱時間６時間の本発明製品８の水素ガス
発生速度は２１０ｍｌ／ｈであり、水熱時間を長くする
ことにより水素ガス発生速度の増加傾向が認められ、２
４時間で最大となっているが、数時間の水熱時間でも高
い水素ガス発生速度を有している。合成プロセスとして
は、短時間で製造できることが望ましいが、水熱合成の
場合、反応容器の放冷時間を考慮する必要がある。本発
明製品の場合には、水熱処理後、反応容器を冷水により
冷却し、放冷時間を極力短かくして行ったが、実用に際
しては反応容器の放冷時間を充分長くする場合には、熱
を加える水熱時間を短縮することが可能と考えられる。The hydrogen gas generation rate of the product 8 of the present invention 8 with a hydrothermal time of 6 hours was 210 ml / h, and the hydrogen gas generation rate tended to increase by increasing the hydrothermal time.
It has a maximum in 4 hours, but has a high hydrogen gas generation rate even in several hours of hydrothermal time. As a synthesis process, it is desirable to be able to produce in a short time, but in the case of hydrothermal synthesis, it is necessary to consider the cooling time of the reaction vessel. In the case of the product of the present invention, after the hydrothermal treatment, the reaction vessel was cooled with cold water, and the cooling time was made as short as possible.However, in practical use, when the cooling time of the reaction vessel was made sufficiently long, heat was applied. It is considered possible to reduce the hydrothermal time to be added.
【００３５】実施例１３ 原料であるチタニウムテトラプロポキシドをチタニウム
テトラエトキシドに代えて水熱合成を行った。２０ｇの
チタニウムテトラエトキシドと蒸留水２００ｍｌを耐圧
テフロン製容器に加え、密封した後、恒温槽にて２００
℃において２４時間保持した。耐圧テフロン製容器を取
り出し、放冷後、沈殿物をろ別、水洗、乾燥させ、４．
１ｇの酸化チタン沈殿物を得た。蒸留水５００ｍｌに、
０. ０２Ｍ白金酸溶液５ｍｌを加え、内部照射型光化学
反応容器に移し、前記沈殿物１gを添加し、室温で約５
時間４００Ｗ高圧水銀ランプを用い照射させた。白金酸
は白金担持量として２ｗｔ％（ｙ＝０. ００８）に想定
して反応させたものである。反応生成物はろ別、水洗、
エタノールで洗浄した後、デシケータを用い室温で乾燥
させ、本発明製品１３を得た。得られた本発明製品のＸ
線回折結果では、アナタース型酸化チタンの（１０
１）、（００４）、（２００）、（１０５）、（２１
１）及び（２０４）に相当すると考えられる２θ＝２
５. ３°、３７. ８°、４８. １°、５３. ９°、５
５. １°及び６２. ７°にブロードなピークが認められ
た。熱重量減量値から求めたｘの値は０. ４５であり、
ｙの値は０. ００８であった。０．３ｇの本発明製品１
３とメタノール水溶液（メタノール：水＝１：３体積
比）６００ｍｌをパイレックス製内部照射型光化学反応
管に加え、３０℃で反応させた。発生したガスの組成を
ガスクロマトグラフィを用い分析し、水素発生速度を求
めた。水素発生速度は３００ｍｌ／ｈであり、高い光触
媒活性を有していることがわかり、原料としてチタニウ
ムテトラエトキシドでも良いことが解る。Example 13 Hydrothermal synthesis was performed by replacing titanium tetrapropoxide as a raw material with titanium tetraethoxide. 20 g of titanium tetraethoxide and 200 ml of distilled water were added to a pressure-resistant Teflon container, sealed, and then placed in a thermostat.
C. for 24 hours. 3. Take out the pressure-resistant Teflon container, allow it to cool, and then separate the precipitate by filtration, wash with water, and dry.
1 g of a titanium oxide precipitate was obtained. In 500 ml of distilled water,
5 ml of a 0.02 M platinic acid solution was added, and the mixture was transferred to an internal irradiation type photochemical reaction vessel, and 1 g of the precipitate was added.
Irradiation was performed using a 400 W high pressure mercury lamp for a time. Platinic acid was reacted under the assumption that the amount of platinum carried was 2 wt% (y = 0.008). The reaction product is filtered, washed with water,
After washing with ethanol, the product was dried at room temperature using a desiccator to obtain a product 13 of the present invention. X of the obtained product of the present invention
According to the results of X-ray diffraction, (10
1), (004), (200), (105), (21)
2θ = 2 considered to correspond to 1) and (204)
5.3 °, 37.8 °, 48.1 °, 53.9 °, 5
Broad peaks were observed at 5.1 ° and 62.7 °. The value of x obtained from the thermogravimetric weight loss value was 0.45,
The value of y was 0.008. 0.3 g of the product 1 of the present invention
3 and 600 ml of a methanol aqueous solution (methanol: water = 1: 3 volume ratio) were added to a Pyrex internal irradiation type photochemical reaction tube, and reacted at 30 ° C. The composition of the generated gas was analyzed using gas chromatography to determine the hydrogen generation rate. The hydrogen generation rate was 300 ml / h, indicating that it had a high photocatalytic activity, indicating that titanium tetraethoxide may be used as a raw material.
【００３６】実施例１４ 原料であるチタニウムテトラプロポキシドに代えてチタ
ニウムテトラブトキシドを用い、水熱合成を行った。２
０ｇのチタニウムテトラブキシドと蒸留水２００ｍｌを
耐圧テフロン製容器に加え、密封した後、恒温槽にて２
００℃において２４時間保持した。耐圧テフロン製容器
を取り出し、放冷後、沈殿物をろ別、水洗、乾燥させ、
４．３ｇの酸化チタン沈殿物を得た。蒸留水５００ｍｌ
に、０.０２Ｍ白金酸溶液５ｍｌを加え、内部照射型光
化学反応容器に移し、前記沈殿物１ｇを添加し、室温で
約５時間４００Ｗ高圧水銀ランプを用い照射させた。白
金酸は白金担持量として２ｗｔ％（ｙ＝０. ００８）に
想定して反応させたものである。反応生成物はろ別、水
洗、エタノールで洗浄した後、デシケータを用い室温で
乾燥させ、本発明製品１４を得た。得られた本発明製品
のＸ線回折結果では、アナタース型酸化チタンの（１０
１）、（００４）、（２００）、（１０５）、（２１
１）及び（２０４）に相当すると考えられる２θ＝２
５. ３°、３７.８°、４８. １°、５３. ９°、５５.
１°及び６２. ７°にブロードなピークが認められ
た。熱重量減量値から求めたｘの値は１. １であり、ｙ
の値は０. ００８であった。０．３ｇの本発明製品１４
とメタノール水溶液（メタノール：水＝１：３体積比）
６００ｍｌをパイレックス製内部照射型光化学反応管に
加え、３０℃で反応させた。発生したガスの組成をガス
クロマトグラフィを用い分析し、水素発生速度を求め
た。水素発生速度は２７４ｍｌ／ｈであり、高い光触媒
活性を有していることがわかり、原料としてチタニウム
テトラブトキシドでも良いことが解る。Example 14 Hydrothermal synthesis was performed using titanium tetrabutoxide instead of titanium tetrapropoxide as a raw material. 2
0 g of titanium tetrabutoxide and 200 ml of distilled water were added to a pressure-resistant Teflon container, sealed, and then placed in a thermostat.
It was kept at 00 ° C. for 24 hours. Take out the pressure-resistant Teflon container, let it cool down, filter the precipitate, wash it with water, and dry it.
4.3 g of titanium oxide precipitate were obtained. 500 ml of distilled water
Then, 5 ml of a 0.02 M platinic acid solution was added, the mixture was transferred to an internal irradiation type photochemical reaction vessel, 1 g of the precipitate was added, and irradiation was performed at room temperature for about 5 hours using a 400 W high pressure mercury lamp. Platinic acid was reacted under the assumption that the amount of platinum carried was 2 wt% (y = 0.008). The reaction product was separated by filtration, washed with water, and washed with ethanol, and then dried at room temperature using a desiccator to obtain a product 14 of the present invention. According to the X-ray diffraction results of the obtained product of the present invention, (10)
1), (004), (200), (105), (21)
2θ = 2 considered to correspond to 1) and (204)
5.3 °, 37.8 °, 48.1 °, 53.9 °, 55.
Broad peaks were observed at 1 ° and 62.7 °. The value of x obtained from the thermogravimetric weight loss value is 1.1, and y
Was 0.008. 0.3 g of the product 14 of the present invention
And methanol aqueous solution (methanol: water = 1: 3 volume ratio)
600 ml was added to a Pyrex internal irradiation type photochemical reaction tube and reacted at 30 ° C. The composition of the generated gas was analyzed using gas chromatography to determine the hydrogen generation rate. The hydrogen generation rate was 274 ml / h, indicating high photocatalytic activity, indicating that titanium tetrabutoxide may be used as a raw material.
【００３７】[0037]
【発明の効果】本発明は、水素ガス発生速度が高い酸化
チタン光触媒及びその製造方法に係るものであり、本発
明により、次のような効果が奏される。 （１）従来の酸化チタン光触媒に比べ、光水素発生速度
が高い。 （２）耐化学性も良好でｐＨ１〜１３の広いｐＨ領域で
用いられうる。 （３）比較的温和な生成条件下での簡便な工程で得るこ
とができる。 （４）生成物がサブミクロン以下の微粒子であり、水溶
液中に分散しやすいので、ガスのバブリングなどの浮遊
化操作を必要としない。 （５）比表面積の値が１００ｍ2 ｇ-1を越える光触媒が
得られる。The present invention relates to a titanium oxide photocatalyst having a high hydrogen gas generation rate and a method for producing the same. The present invention has the following effects. (1) The photohydrogen generation rate is higher than the conventional titanium oxide photocatalyst. (2) It has good chemical resistance and can be used in a wide pH range of pH 1 to 13. (3) It can be obtained in a simple step under relatively mild production conditions. (4) Since the product is fine particles of submicron size or less and is easily dispersed in an aqueous solution, a floating operation such as gas bubbling is not required. (5) A photocatalyst having a specific surface area exceeding 100 m 2 g −1 is obtained.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 蛯名 武雄 宮城県仙台市宮城野区清水沼２丁目３番６ 号 泉荘202号 (72)発明者 長瀬 多加子 宮城県仙台市宮城野区宮千代２丁目８番 ４−101号 (72)発明者 鳥居 一雄 宮城県仙台市太白区西中田１丁目19−13 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeo Ebina 2-3-6, Shimizunuma, Miyagino-ku, Sendai, Miyagi Prefecture Izumiso 202 (72) Inventor Takako Nagase 2--8, Miyachiyo, Miyagino-ku, Sendai, Miyagi Prefecture No. 4-101 (72) Inventor Kazuo Torii 1-19-13 Nishinakada, Taihaku-ku, Sendai, Miyagi
Claims (7)
５未満の数である）で表される酸化チタン光触媒。The basic structure is represented by a general formula TiO 2 .xH 2 O.yPt (where x is a number from 0 to 1.5, and y is greater than 0 and 0.0
A titanium oxide photocatalyst represented by the formula:
タースであることを特徴とする請求項１記載の酸化チタ
ン光触媒。2. The titanium oxide photocatalyst according to claim 1, wherein the titanium oxide as a carrier has an anatase crystal structure.
合して、沈殿物を生成させ、水熱条件下で処理して得ら
れた反応生成物をろ過・水洗し、必要に応じて乾燥した
後、白金含有溶液に浸漬し、紫外光を照射することを特
徴とする基本構造が、一般式 ＴｉＯ2 ・ｘＨ2 Ｏ・ｙＰｔ （式中のｘは０〜１. ５の数、ｙは０より大きく０. ０
５未満の数である）で表される酸化チタン光触媒の製造
方法。3. Titanium tetraalkoxide is mixed with water to form a precipitate, and a reaction product obtained by treatment under hydrothermal conditions is filtered, washed with water, and dried if necessary. The basic structure characterized by being immersed in a containing solution and irradiating with ultraviolet light is represented by a general formula TiO 2 .xH 2 O.yPt (where x is a number of 0 to 1.5, y is greater than 0 and 0 . 0
The number is less than 5).
合して、沈殿物を生成させ、水熱条件下で処理して得ら
れた反応生成物をろ過・水洗し、必要に応じて乾燥した
後、白金含有溶液に浸漬し、紫外光を照射することを特
徴とする担体である酸化チタンの結晶構造がアナタース
である請求項３記載の酸化チタン光触媒の製造方法。4. Titanium tetraalkoxide is mixed with water to form a precipitate, and the reaction product obtained by the treatment under hydrothermal conditions is filtered, washed with water, and, if necessary, dried. 4. The method for producing a titanium oxide photocatalyst according to claim 3, wherein the titanium oxide as a carrier has an anatase crystal structure, which is immersed in a solution containing the solution and irradiated with ultraviolet light.
エトキシド、プロポキシド、ブトキシドを原料として使
用することを特徴とする請求項３又は請求項４記載の酸
化チタン光触媒の製造方法。5. A titanium tetraalkoxide,
The method for producing a titanium oxide photocatalyst according to claim 3 or 4, wherein ethoxide, propoxide, or butoxide is used as a raw material.
を特徴とする請求項３、請求項４又は請求項５記載の酸
化チタン光触媒の製造方法。6. The method for producing a titanium oxide photocatalyst according to claim 3, wherein the hydrothermal treatment temperature is 100 ° C. or higher.
特徴とする請求項３、請求項４、請求項５又は請求項６
記載の酸化チタン光触媒の製造方法。7. The hydrothermal treatment time is not less than 6 hours.
A method for producing the titanium oxide photocatalyst described above.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010202456A (en) * | 2009-03-03 | 2010-09-16 | Graduate School For The Creation Of New Photonics Industries | Production method of fine particle |
| JP2011236074A (en) * | 2010-05-10 | 2011-11-24 | Mie Univ | Hydrogen producing method using nano-composite semiconductor photocatalyst material and methanol aqueous solution |
| JP2012206933A (en) * | 2011-03-14 | 2012-10-25 | Daicel Corp | Method for purifying fine particle, and method for producing titanium oxide fine particle supporting transition metal compound, including the purification method of the fine particle |
| JP2012254451A (en) * | 2011-05-18 | 2012-12-27 | Daicel Corp | Adjustment method of transition metal compound support quantity in transition metal compound support titanium oxide |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5229947B2 (en) * | 2008-11-17 | 2013-07-03 | 中部電力株式会社 | Semiconductor photocatalytic substance, method for producing the same, and method for producing hydrogen |
| US10668462B2 (en) | 2017-02-09 | 2020-06-02 | King Abdulaziz University | Multiphasic titanium dioxide photocatalyst for the reduction of carbon dioxide |
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1999
- 1999-09-20 JP JP11265825A patent/JP3136339B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010202456A (en) * | 2009-03-03 | 2010-09-16 | Graduate School For The Creation Of New Photonics Industries | Production method of fine particle |
| JP2011236074A (en) * | 2010-05-10 | 2011-11-24 | Mie Univ | Hydrogen producing method using nano-composite semiconductor photocatalyst material and methanol aqueous solution |
| JP2012206933A (en) * | 2011-03-14 | 2012-10-25 | Daicel Corp | Method for purifying fine particle, and method for producing titanium oxide fine particle supporting transition metal compound, including the purification method of the fine particle |
| JP2012254451A (en) * | 2011-05-18 | 2012-12-27 | Daicel Corp | Adjustment method of transition metal compound support quantity in transition metal compound support titanium oxide |
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