JP3579082B2 - Photocatalyst - Google Patents
Photocatalyst Download PDFInfo
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- JP3579082B2 JP3579082B2 JP09371894A JP9371894A JP3579082B2 JP 3579082 B2 JP3579082 B2 JP 3579082B2 JP 09371894 A JP09371894 A JP 09371894A JP 9371894 A JP9371894 A JP 9371894A JP 3579082 B2 JP3579082 B2 JP 3579082B2
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- JP
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- Prior art keywords
- titanium oxide
- vanadium compound
- photocatalyst
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- 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.)
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- 239000011941 photocatalyst Substances 0.000 title claims description 35
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims description 71
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 70
- 150000003682 vanadium compounds Chemical class 0.000 claims description 47
- 239000002245 particle Substances 0.000 claims description 22
- 229910010413 TiO 2 Inorganic materials 0.000 claims description 14
- 238000000034 method Methods 0.000 description 23
- 230000001699 photocatalysis Effects 0.000 description 15
- 239000000126 substance Substances 0.000 description 15
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 12
- 238000013032 photocatalytic reaction Methods 0.000 description 9
- 239000000725 suspension Substances 0.000 description 9
- 150000003609 titanium compounds Chemical class 0.000 description 9
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- 239000003513 alkali Substances 0.000 description 4
- UNTBPXHCXVWYOI-UHFFFAOYSA-O azanium;oxido(dioxo)vanadium Chemical compound [NH4+].[O-][V](=O)=O UNTBPXHCXVWYOI-UHFFFAOYSA-O 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 229910000349 titanium oxysulfate Inorganic materials 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 150000001412 amines Chemical class 0.000 description 3
- 229910021529 ammonia Inorganic materials 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 230000003472 neutralizing effect Effects 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 150000002896 organic halogen compounds Chemical class 0.000 description 3
- XJDNKRIXUMDJCW-UHFFFAOYSA-J titanium tetrachloride Chemical compound Cl[Ti](Cl)(Cl)Cl XJDNKRIXUMDJCW-UHFFFAOYSA-J 0.000 description 3
- 241000186361 Actinobacteria <class> Species 0.000 description 2
- 241000195493 Cryptophyta Species 0.000 description 2
- 241000233866 Fungi Species 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 150000001299 aldehydes Chemical class 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000003344 environmental pollutant Substances 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000006460 hydrolysis reaction Methods 0.000 description 2
- 230000003301 hydrolyzing effect Effects 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- 229910017464 nitrogen compound Inorganic materials 0.000 description 2
- 150000002830 nitrogen compounds Chemical class 0.000 description 2
- 230000006911 nucleation Effects 0.000 description 2
- 238000010899 nucleation Methods 0.000 description 2
- 150000002903 organophosphorus compounds Chemical class 0.000 description 2
- 230000001443 photoexcitation Effects 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- LLZRNZOLAXHGLL-UHFFFAOYSA-J titanic acid Chemical compound O[Ti](O)(O)O LLZRNZOLAXHGLL-UHFFFAOYSA-J 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- -1 titanyl sulfate Chemical class 0.000 description 2
- LSGOVYNHVSXFFJ-UHFFFAOYSA-N vanadate(3-) Chemical class [O-][V]([O-])([O-])=O LSGOVYNHVSXFFJ-UHFFFAOYSA-N 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 1
- 241000894006 Bacteria Species 0.000 description 1
- 208000035985 Body Odor Diseases 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical class S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- 241000208125 Nicotiana Species 0.000 description 1
- 235000002637 Nicotiana tabacum Nutrition 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- CYTYCFOTNPOANT-UHFFFAOYSA-N Perchloroethylene Chemical group ClC(Cl)=C(Cl)Cl CYTYCFOTNPOANT-UHFFFAOYSA-N 0.000 description 1
- 206010040904 Skin odour abnormal Diseases 0.000 description 1
- XSTXAVWGXDQKEL-UHFFFAOYSA-N Trichloroethylene Chemical group ClC=C(Cl)Cl XSTXAVWGXDQKEL-UHFFFAOYSA-N 0.000 description 1
- XHCLAFWTIXFWPH-UHFFFAOYSA-N [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] Chemical class [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] XHCLAFWTIXFWPH-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000003915 air pollution Methods 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- 150000001413 amino acids Chemical class 0.000 description 1
- 239000001099 ammonium carbonate Substances 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 150000001845 chromium compounds Chemical class 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010411 cooking Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 239000002781 deodorant agent Substances 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 239000000417 fungicide Substances 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 239000000383 hazardous chemical Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000004009 herbicide Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000010335 hydrothermal treatment Methods 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000002917 insecticide Substances 0.000 description 1
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000005645 nematicide Substances 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical class [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 description 1
- IYVLHQRADFNKAU-UHFFFAOYSA-N oxygen(2-);titanium(4+);hydrate Chemical compound O.[O-2].[O-2].[Ti+4] IYVLHQRADFNKAU-UHFFFAOYSA-N 0.000 description 1
- 239000000575 pesticide Substances 0.000 description 1
- 150000003071 polychlorinated biphenyls Chemical group 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000001954 sterilising effect Effects 0.000 description 1
- 238000004659 sterilization and disinfection Methods 0.000 description 1
- 150000003464 sulfur compounds Chemical class 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 229950011008 tetrachloroethylene Drugs 0.000 description 1
- UBOXGVDOUJQMTN-UHFFFAOYSA-N trichloroethylene Natural products ClCC(Cl)Cl UBOXGVDOUJQMTN-UHFFFAOYSA-N 0.000 description 1
- 229910001456 vanadium ion Inorganic materials 0.000 description 1
- 229910001935 vanadium oxide Inorganic materials 0.000 description 1
- VLOPEOIIELCUML-UHFFFAOYSA-L vanadium(2+);sulfate Chemical compound [V+2].[O-]S([O-])(=O)=O VLOPEOIIELCUML-UHFFFAOYSA-L 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Physical Water Treatments (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Catalysts (AREA)
Description
【０００１】
【産業上の利用分野】
本発明は優れた光触媒機能を有する酸化チタン光触媒体に関する。
【０００２】
【従来の技術】
酸化チタンにそのバンドギャップ以上のエネルギーを持つ波長の光を照射すると光励起により伝導帯に電子を、価電子帯に正孔を生じる。この光励起により生じた電子の持つ強い還元力や正孔の持つ強い酸化力は、有害物質の分解・浄化、アンモニア、アルデヒド類、アミン類などの悪臭ガスの脱臭のほか、水の分解、細菌、放線菌、菌類、藻類などの殺菌・殺藻などの光触媒反応に利用されている。たとえば、特公平２−９８５０号公報には、酸化チタンなどの光触媒を用いて廃棄物中の有害物質を分解し、浄化することが記載されている。また、特公平４−７８３２６号公報には、酸化チタンなどの光触媒を用いてトイレのし尿臭、ペットの臭い、たばこの臭い、調理臭、体臭などを脱臭することが記載されている。さらに、特公平４−２９３９３号公報には、光照射により酸化チタンなどの光触媒に生起した所定電圧を細胞に接触印可して細胞を殺すことが記載されている。
【０００３】
【発明が解決しようとする課題】
前記の光触媒反応に用いる光触媒体は、光触媒反応の処理時間を短縮したり、光触媒反応に用いる装置を小型化したりするため、一層優れた光触媒機能を有する光触媒体が嘱望されているが、充分満足できる光触媒体はない。
【０００４】
【課題を解決するための手段】
本発明者らは、優れた光触媒機能を有する酸化チタン光触媒体を得るべく研究した結果、（１）酸化チタンにバナジウム化合物を含有させると、酸化チタンの光触媒機能が向上すること、（２）酸化チタン粒子の表面にバナジウム化合物を担持すると、酸化チタンの光触媒機能がさらに向上することなどを見出し、本発明を完成した。
すなわち、本発明は優れた光触媒機能を有する酸化チタン光触媒体を提供することにある。
【０００５】
本発明は、平均粒子径５〜５０ｎｍの酸化チタンと、該酸化チタンのＴｉＯ 2 重量基準に対して、Ｖ基準に換算して０．００３〜０．３重量％の量のバナジウム化合物とを含有している光触媒体である。本発明の光触媒体は、酸化チタンとバナジウム化合物との単なる混合物、酸化チタン粒子の内部にバナジウム化合物が取り込まれている状態を保持した粒子、酸化チタン粒子の表面にバナジウム化合物が担持されている状態を保持した粒子が好ましい。本発明において、酸化チタンとはアナタース型酸化チタン、ルチル型酸化チタン、無定形酸化チタン、メタチタン酸、オルトチタン酸などの各種の酸化チタンあるいは水酸化チタン、含水酸化チタンを意味する。酸化チタンの平均粒子径は、Ｓｃｈｅｒｒｅｒの式より算出して、１〜５００ｎｍ、好ましくは５〜２５０ｎｍ、もっとも好ましくは５〜５０ｎｍである。また、本発明において、バナジウム化合物は、バナジウムの酸化物、水酸化物、硫酸塩、ハロゲン化物、硝酸塩、アシド錯化合物やバナジウム酸塩、さらにはバナジウムイオンを含む。バナジウム化合物の含有量は、対象とする光触媒反応により任意に変えられるが、酸化チタンのＴｉＯ2 重量基準に対して、バナジウム化合物をＶ基準に換算して０．０００５〜１０重量％、好ましくは０．００１〜５重量％、より好ましくは０．００１〜３重量％、もっとも好ましくは０．００１〜１重量％である。バナジウム化合物が前記範囲より少なかったり、また逆に多かったりすると光触媒機能が低下する傾向にある。
【０００６】
本発明においては、光触媒体に含まれるバナジウム化合物は、酸化チタン粒子の表面に担持されている状態がもっとも好ましく、この場合のバナジウム化合物の担持量は酸化チタン粒子の表面積１ｍ２ 当たり、バナジウム化合物をＶ基準に換算して０．０５〜５０００μｇ、好ましくは０．１〜３０００μｇ、より好ましくは０．１〜２０００μｇ、もっとも好ましくは０．３〜１０００μｇである。バナジウム化合物が前記範囲より少なかったり、また逆に多かったりすると光触媒機能が低下する傾向にある。
【０００７】
本発明の酸化チタンとバナジウム化合物とを含有した光触媒体は種々の方法によって得ることができる。たとえば、▲１▼酸化チタンとバナジウム化合物とを機械的に混合する方法、▲２▼硫酸チタニル、塩化チタン、有機チタン化合物などのチタン化合物をバナジウム化合物の存在下に、必要に応じてさらに核形成用種子の存在下に、チタン化合物を加水分解あるいは中和する方法、▲３▼バナジウム化合物の溶液に酸化チタン粒子あるいは酸化チタン粒子を保持した支持体を浸漬する方法、▲４▼酸化チタン粒子の懸濁液あるいは酸化チタン粒子を保持した支持体を入れた液にバナジウム化合物を添加し、バナジウム化合物を中和する方法などがあるが、これらの方法は、優れた特性のものが得られるため好ましいものである。前記の▲３▼、▲４▼の方法によると、酸化チタン粒子の表面にバナジウム化合物を担持できる。前記の方法に用いるバナジウム化合物としては、たとえば、バナジウムの硫酸塩、塩化物、硝酸塩、バナジウム酸塩などの水可溶性バナジウム化合物が好ましい。また、中和に用いるアルカリとしては、たとえば、水酸化ナトリウム、水酸化カリウム、炭酸アンモニウム、アンモニア、アミン類など種々のアルカリが挙げられる。
【０００８】
前記▲３▼、▲４▼の方法において用いる酸化チタン粒子は種々の公知の方法で得ることができる。その方法としては、たとえば、（ｉ）硫酸チタニル、塩化チタン、有機チタン化合物などのチタン化合物を、必要に応じて核形成用種子の存在下に、加水分解する方法、（ｉｉ）硫酸チタニル、塩化チタン、有機チタン化合物などのチタン化合物に、必要に応じて核形成用種子の存在下に、アルカリを添加し、中和する方法、（ｉｉｉ）塩化チタン、有機チタン化合物などを気相酸化する方法、（ｉｖ）前記（ｉ）、（ｉｉ）、（ｉｉｉ）の方法で得た酸化チタンを焼成、あるいは、酸化チタンの懸濁液を、必要に応じて酸またはアルカリを加え、水熱処理する方法などがあり、前記（ｉ）、（ｉｉ）、（ｉｖ）の方法で得られた酸化チタンを用いると優れた光触媒機能を有する光触媒体が得られるため好ましい。
【０００９】
前記の▲１▼〜▲４▼の方法において得られた生成物を本発明の光触媒体として用いることができるが、必要に応じて、該生成物を分別し、洗浄し、乾燥あるいは焼成してもよい。分別は通常の濾過や傾斜法などの方法によって行うことができる。乾燥は任意の温度で行うことができるが、１００〜２００℃の温度が適当である。焼成の温度は２００〜８００℃の温度が適当である。なお、本発明の方法においては、バナジウム化合物、チタン化合物、アルカリなどの濃度および添加速度、加水分解反応や中和反応の温度、分散液中の酸化チタンの濃度などの条件は、特に制限がなく適宜設定することができる。
【００１０】
本発明の光触媒体を、有機物質の合成反応や有害物質の分解反応などの種々の光触媒反応に用いるには、処理対象物質の存在下、該光触媒体にそのバンドギャップ以上のエネルギーを持つ波長の光を照射する。本発明の光触媒体は、使用場面に応じて、溶媒に懸濁した状態、支持体に保持あるいは被覆した状態、該光触媒体を粉末の状態、あるいは該粉末を粉砕した状態、さらには、該粉末を成形した状態で用いることもできる。酸化チタンの光触媒反応により分解あるいは酸化して除去する有害物質としては、人体や生活環境に悪影響を及ぼす物質やその可能性がある物質であり、たとえば、種々の生物学的酸素要求物質、大気汚染物質などの環境汚染物質や除草剤、殺菌剤、殺虫剤、殺線虫剤などの種々の農薬などの物質、細菌、放線菌、菌類、藻類、カビ類などの微生物などが挙げられる。環境汚染物質としては、有機ハロゲン化合物、有機リン化合物やそれ以外の有機化合物、窒素化合物、硫黄化合物、シアン化合物、クロム化合物などの無機化合物が挙げられる。有機ハロゲン化合物としては、具体的には、ポリ塩化ビフェニル、フロン、トリハロメタン、トリクロロエチレン、テトラクロロエチレンが例示できる。有機ハロゲン化合物、有機リン化合物以外の有機物質としては、具体的には、界面活性剤や油類などの炭化水素類、アルデヒド類、メルカプタン類、アルコール類、アミン類、アミノ酸、蛋白質が例示できる。また、窒素化合物としては、具体的には、アンモニア、窒素酸化物が例示できる。バンドギャップ以上のエネルギーを持つ波長の光としては、紫外線を含有した光が好ましく、たとえば、太陽光や蛍光灯、ブラックライト、ハロゲンランプ、キセノンフラッシュランプ、水銀灯などの光を用いることができる。特に３００〜４００ｎｍの近紫外線を含有した光が好ましい。光の照射量や照射時間などは処理対象物質の量などによって適宜設定できる。
【００１１】
【実施例】
実施例１
８０ｇ／ｌの硫酸チタニルの水溶液１リットルを８５℃の温度に加熱し３時間保持して、硫酸チタニルを加水分解した。このようにして得られた加水分解生成物を濾過し、洗浄した後、水に懸濁させ、ＴｉＯ２ に換算して５０ｇ／ｌの懸濁液とした。次いで、前記の懸濁液に硝酸水溶液を添加して液のｐＨを１．０に調整した後、該懸濁液をオートクレーブに入れ、飽和蒸気圧下、１８０℃の温度で１３時間水熱処理した。この後、得られた生成物を濾過し、洗浄し、乾燥し、次いで、５００℃の温度で２時間焼成して、酸化チタン（試料１）を得た。なお、試料１の比表面積は５１．５ｍ２ ／ｇであり、アナタース型結晶を有しており、Ｓｃｈｅｒｒｅｒの式から求めた平均粒子径は１８．２ｎｍであった。
前記の試料１の酸化チタン１０ｇを水に懸濁させ、ＴｉＯ２ に換算して１００ｇ／ｌの懸濁液とした。次いで、前記の懸濁液に攪拌下、バナジウム酸アンモニウム（ＮＨ４ ＶＯ３ ）０．６９ｍｇを溶解した水溶液を添加し、１６時間攪拌した後、濾過し、洗浄し、乾燥して、本発明のバナジウム化合物を含有した酸化チタン光触媒体（試料Ａ）を得た。この試料Ａは、酸化チタンのＴｉＯ２ 重量基準に対して、Ｖ基準に換算して０．００３重量％のバナジウム化合物を含有しており、酸化チタン粒子の表面積１ｍ２ 当たりのバナジウム化合物の担持量はＶ基準に換算して０．５８μｇであった。
【００１２】
実施例２
実施例１において、バナジウム酸アンモニウム（ＮＨ４ ＶＯ３ ）６．８９ｍｇを溶解した水溶液を用いたこと以外は、実施例１と同様に処理して、本発明のバナジウム化合物を含有した酸化チタン光触媒体（試料Ｂ）を得た。この試料Ｂは、酸化チタンのＴｉＯ２ 重量基準に対して、Ｖ基準に換算して０．０３重量％のバナジウム化合物を含有しており、酸化チタン粒子の表面積１ｍ２ 当たりのバナジウム化合物の担持量はＶ基準に換算して５．８３μｇであった。
【００１３】
実施例３
実施例１において、バナジウム酸アンモニウム（ＮＨ４ ＶＯ３ ）６８．９ｍｇを溶解した水溶液を用いたこと以外は、実施例１と同様に処理して、本発明のバナジウム化合物を含有した酸化チタン光触媒体（試料Ｃ）を得た。この試料Ｃは、酸化チタンのＴｉＯ２ 重量基準に対して、Ｖ基準に換算して０．３重量％のバナジウム化合物を含有しており、酸化チタン粒子の表面積１ｍ２ 当たりのバナジウム化合物の担持量はＶ基準に換算して５８．３μｇであった。
【００１４】
実施例４
前記の試料１の酸化チタン１０ｇを、バナジウム酸アンモニウム（ＮＨ４ ＶＯ３ ）６．８９ｍｇを溶解した水溶液に浸漬し、次いで、蒸発乾固し、さらに、１１０℃の温度で乾燥して、本発明のバナジウム化合物を含有した酸化チタン光触媒体（試料Ｄ）を得た。この試料Ｄは、酸化チタンのＴｉＯ２ 重量基準に対して、Ｖ基準に換算して０．０３重量％のバナジウム化合物を含有しており、酸化チタン粒子の表面積１ｍ２ 当たりのバナジウム化合物の担持量はＶ基準に換算して５．８３μｇであった。
【００１５】
実施例５
前記の実施例４で得られた試料Ｄを、２００℃の温度で３時間焼成して、本発明のバナジウム化合物を含有した酸化チタン光触媒体（試料Ｅ）を得た。この試料Ｅは、酸化チタンのＴｉＯ２ 重量基準に対して、Ｖ基準に換算して０．０３重量％のバナジウム化合物を含有していた。
【００１６】
実施例６
前記の実施例４で得られた試料Ｄを、３００℃の温度で３時間焼成して、本発明のバナジウム化合物を含有した酸化チタン光触媒体（試料Ｆ）を得た。この試料Ｆは、酸化チタンのＴｉＯ２ 重量基準に対して、Ｖ基準に換算して０．０３重量％のバナジウム化合物を含有していた。
【００１７】
実施例７
前記の実施例４で得られた試料Ｄを、５００℃の温度で３時間焼成して、本発明のバナジウム化合物を含有した酸化チタン光触媒体（試料Ｇ）を得た。この試料Ｇは、酸化チタンのＴｉＯ２ 重量基準に対して、Ｖ基準に換算して０．０３重量％のバナジウム化合物を含有していた。
【００１８】
比較例１
実施例１において得られた試料１の酸化チタンを比較試料Ｈとして用いた。
【００１９】
実施例および比較例で得られた試料（Ａ〜Ｈ）の光触媒機能を以下のようにして調べた。各試料０．１ｇを純水に分散させ、ＴｉＯ２ に換算して４ｇ／ｌの懸濁液とした。これらの懸濁液２５ｍｌに２−プロパノール２５μｌを添加した後、ブラックライト（ピーク波長３６５ｎｍ）を２時間照射して、２−プロパノールの光触媒反応を行った。光量は２ｍＷ／ｃｍ２ であった。反応前の２−プロパノールの濃度と反応後の２−プロパノールの濃度から各々の試料による分解速度を算出した。その結果を表１に示す。この表から明らかなように、本発明の酸化チタン光触媒体は光触媒機能に優れていることがわかった。また、本発明の酸化チタン光触媒体は熱による光触媒機能の劣化が少ないため、高温度での光触媒反応に用いることができ、また、本発明の酸化チタン光触媒体を加熱して支持体に接着させることができる。
【００２０】
【表１】
【発明の効果】
本発明の酸化チタン光触媒は、酸化チタンとバナジウム化合物とを含有してなるものであって、バナジウム化合物を含有させることにより酸化チタンの光触媒機能を向上させることができる。特に、酸化チタン粒子の表面にバナジウム化合物を担持すると、より一層酸化チタンの光触媒機能を向上させることができる。本発明の光触媒体の光触媒機能を利用して人体や生活環境に悪影響を及ぼす物質やその可能性がある物質を迅速、かつ、効率よく除去することができるので、工業用途ばかりでなく一般家庭用の脱臭体、殺菌体などとして極めて有用なものである。また、本発明の酸化チタン光触媒は、安全性が高く、さらに、廃棄しても環境を汚さないため、種々の用途に用いることができる。[0001]
[Industrial applications]
The present invention relates to a titanium oxide photocatalyst having an excellent photocatalytic function.
[0002]
[Prior art]
When the titanium oxide is irradiated with light having a wavelength having energy equal to or greater than the band gap, photoexcitation generates electrons in the conduction band and holes in the valence band. The strong reducing power of electrons and the strong oxidizing power of holes generated by this photoexcitation are used to decompose and purify harmful substances, deodorize ammonia, aldehydes, amines, and other odorous gases, as well as decompose water, It is used for photocatalytic reactions such as sterilization and algicidation of actinomycetes, fungi and algae. For example, Japanese Patent Publication No. 2-9850 describes that harmful substances in waste are decomposed and purified using a photocatalyst such as titanium oxide. Further, Japanese Patent Publication No. 4-78326 discloses that a photocatalyst such as titanium oxide is used to deodorize toilet odor, pet odor, tobacco odor, cooking odor, body odor, and the like. Furthermore, Japanese Patent Publication No. 4-29393 describes that a predetermined voltage generated in a photocatalyst such as titanium oxide by light irradiation is applied to a cell to kill the cell.
[0003]
[Problems to be solved by the invention]
As for the photocatalyst used for the photocatalytic reaction, a photocatalyst having a more excellent photocatalytic function is expected to shorten the processing time of the photocatalytic reaction or to reduce the size of an apparatus used for the photocatalytic reaction. There are no photocatalysts available.
[0004]
[Means for Solving the Problems]
The present inventors have studied to obtain a titanium oxide photocatalyst having an excellent photocatalytic function. As a result, (1) that when a titanium oxide contains a vanadium compound, the photocatalytic function of titanium oxide is improved; The present inventors have found that when a vanadium compound is supported on the surface of titanium particles, the photocatalytic function of titanium oxide is further improved, and the present invention has been completed.
That is, the present invention is to provide a titanium oxide photocatalyst having an excellent photocatalytic function.
[0005]
The present invention provides a titanium oxide having an average particle diameter of 5 to 50 nm, and TiO 2 of the titanium oxide. It is a photocatalyst containing a vanadium compound in an amount of 0.003 to 0.3% by weight in terms of V based on weight . The photocatalyst of the present invention is a mere mixture of titanium oxide and a vanadium compound, particles in which a state in which a vanadium compound is incorporated in titanium oxide particles, and a state in which a vanadium compound is supported on the surface of titanium oxide particles. Are preferred. In the present invention, the titanium oxide means various titanium oxides such as anatase-type titanium oxide, rutile-type titanium oxide, amorphous titanium oxide, metatitanic acid and orthotitanic acid, or titanium hydroxide and titanium oxide hydrate. The average particle size of the titanium oxide is 1 to 500 nm, preferably 5 to 250 nm, and most preferably 5 to 50 nm, calculated from the Scherrer's formula. In the present invention, the vanadium compound includes vanadium oxides, hydroxides, sulfates, halides, nitrates, acid complex compounds, vanadates, and vanadium ions. The content of the vanadium compound can be arbitrarily changed depending on the target photocatalytic reaction, and the content of the vanadium compound is 0.0005 to 10% by weight, preferably 0%, in terms of V based on TiO 2 weight of titanium oxide. 0.001 to 5% by weight, more preferably 0.001 to 3% by weight, most preferably 0.001 to 1% by weight. If the amount of the vanadium compound is smaller than the above range or larger than the above range, the photocatalytic function tends to decrease.
[0006]
In the present invention, the state in which the vanadium compound contained in the photocatalyst is supported on the surface of the titanium oxide particles is most preferable. In this case, the amount of the vanadium compound supported is such that the vanadium compound is used per 1 m 2 of the surface area of the titanium oxide particles. It is 0.05 to 5000 µg, preferably 0.1 to 3000 µg, more preferably 0.1 to 2000 µg, most preferably 0.3 to 1000 µg in terms of V standard. If the amount of the vanadium compound is smaller than the above range or larger than the above range, the photocatalytic function tends to decrease.
[0007]
The photocatalyst containing the titanium oxide and the vanadium compound of the present invention can be obtained by various methods. For example, (1) a method of mechanically mixing titanium oxide and a vanadium compound, (2) a titanium compound such as titanyl sulfate, titanium chloride, or an organic titanium compound is further nucleated in the presence of the vanadium compound, if necessary. (3) a method of hydrolyzing or neutralizing a titanium compound in the presence of seeds for use, (3) a method of immersing titanium oxide particles or a support holding titanium oxide particles in a solution of a vanadium compound, (4) a method of There is a method of adding a vanadium compound to a suspension or a solution containing a support holding titanium oxide particles, and a method of neutralizing the vanadium compound.However, these methods are preferable because excellent properties are obtained. Things. According to the above methods (3) and (4), the vanadium compound can be supported on the surface of the titanium oxide particles. As the vanadium compound used in the above-mentioned method, for example, water-soluble vanadium compounds such as vanadium sulfate, chloride, nitrate and vanadate are preferable. Examples of the alkali used for neutralization include various alkalis such as sodium hydroxide, potassium hydroxide, ammonium carbonate, ammonia, and amines.
[0008]
The titanium oxide particles used in the methods (3) and (4) can be obtained by various known methods. Examples of the method include (i) a method of hydrolyzing a titanium compound such as titanyl sulfate, titanium chloride, or an organic titanium compound in the presence of seeds for nucleation, if necessary; A method of neutralizing by adding an alkali to a titanium compound such as titanium or an organic titanium compound in the presence of seeds for nucleation as necessary, and (iii) a method of vapor-phase oxidation of titanium chloride, an organic titanium compound or the like. (Iv) a method of calcining the titanium oxide obtained by the method of (i), (ii) or (iii), or subjecting the suspension of titanium oxide to acid heat or alkali heat treatment as necessary. It is preferable to use the titanium oxide obtained by the methods (i), (ii), and (iv) because a photocatalyst having an excellent photocatalytic function can be obtained.
[0009]
The product obtained in the above methods (1) to (4) can be used as the photocatalyst of the present invention. If necessary, the product is separated, washed, dried or calcined. Is also good. Separation can be performed by a method such as ordinary filtration or a gradient method. Drying can be performed at any temperature, but a temperature of 100 to 200 ° C. is appropriate. The firing temperature is suitably from 200 to 800 ° C. In the method of the present invention, the conditions such as the concentration and addition rate of the vanadium compound, the titanium compound and the alkali, the temperature of the hydrolysis reaction and the neutralization reaction, and the concentration of the titanium oxide in the dispersion are not particularly limited. It can be set appropriately.
[0010]
In order to use the photocatalyst of the present invention for various photocatalytic reactions such as a synthesis reaction of an organic substance and a decomposition reaction of a harmful substance, in the presence of a substance to be treated, the photocatalyst has a wavelength having energy equal to or more than its band gap. Irradiate light. The photocatalyst of the present invention is, depending on the use scene, suspended in a solvent, held or coated on a support, powdered the photocatalyst, or crushed powder, Can be used in a molded state. Hazardous substances that are decomposed or oxidized and removed by the photocatalytic reaction of titanium oxide include substances that have a negative effect on the human body and living environment, and substances that have the potential for such harmful substances. For example, various biological oxygen demanding substances, air pollution Examples include environmental pollutants such as substances, substances such as various pesticides such as herbicides, fungicides, insecticides, nematicides, and microorganisms such as bacteria, actinomycetes, fungi, algae, and molds. Examples of the environmental pollutants include organic halogen compounds, organic phosphorus compounds and other organic compounds, and inorganic compounds such as nitrogen compounds, sulfur compounds, cyanide compounds, and chromium compounds. Specific examples of the organic halogen compound include polychlorinated biphenyl, freon, trihalomethane, trichloroethylene, and tetrachloroethylene. Specific examples of the organic substance other than the organic halogen compound and the organic phosphorus compound include hydrocarbons such as surfactants and oils, aldehydes, mercaptans, alcohols, amines, amino acids, and proteins. In addition, specific examples of the nitrogen compound include ammonia and nitrogen oxides. As light having a wavelength having an energy equal to or greater than the band gap, light containing ultraviolet light is preferable. For example, light from sunlight, a fluorescent lamp, a black light, a halogen lamp, a xenon flash lamp, a mercury lamp, or the like can be used. In particular, light containing near-ultraviolet light of 300 to 400 nm is preferable. The irradiation amount and irradiation time of light can be appropriately set depending on the amount of the substance to be treated.
[0011]
【Example】
Example 1
One liter of an aqueous solution of 80 g / l titanyl sulfate was heated to a temperature of 85 ° C. and held for 3 hours to hydrolyze titanyl sulfate. Thus it was filtered and the resulting hydrolysis product, after washing, suspended in water, and the suspension of 50 g / l in terms of TiO 2. Next, an aqueous nitric acid solution was added to the suspension to adjust the pH of the solution to 1.0, and then the suspension was placed in an autoclave and subjected to hydrothermal treatment at a temperature of 180 ° C. for 13 hours under a saturated vapor pressure. Thereafter, the obtained product was filtered, washed, dried, and then calcined at a temperature of 500 ° C. for 2 hours to obtain titanium oxide (sample 1). Sample 1 had a specific surface area of 51.5 m 2 / g, had an anatase-type crystal, and had an average particle diameter of 18.2 nm determined by Scherrer's equation.
Titanium oxide 10g of the sample 1 of the suspended in water to obtain a suspension of 100 g / l in terms of TiO 2. Next, an aqueous solution in which 0.69 mg of ammonium vanadate (NH 4 VO 3 ) was dissolved was added to the suspension under stirring, followed by stirring for 16 hours, followed by filtration, washing and drying to obtain the present invention. A titanium oxide photocatalyst containing a vanadium compound (sample A) was obtained. This sample A contains 0.003% by weight of a vanadium compound in terms of V based on TiO 2 weight of titanium oxide, and the amount of the vanadium compound carried per 1 m 2 of the surface area of the titanium oxide particles. Was 0.58 μg in terms of V standard.
[0012]
Example 2
In Example 1, a titanium oxide photocatalyst containing the vanadium compound of the present invention was treated in the same manner as in Example 1 except that an aqueous solution in which 6.89 mg of ammonium vanadate (NH 4 VO 3 ) was dissolved was used. (Sample B) was obtained. This sample B contains 0.03% by weight of a vanadium compound in terms of V based on TiO 2 weight of titanium oxide, and the amount of the vanadium compound carried per 1 m 2 of the surface area of the titanium oxide particles. Was 5.83 μg in terms of V standard.
[0013]
Example 3
In Example 1, a titanium oxide photocatalyst containing the vanadium compound of the present invention was treated in the same manner as in Example 1 except that an aqueous solution in which 68.9 mg of ammonium vanadate (NH 4 VO 3 ) was dissolved was used. (Sample C) was obtained. This sample C contains 0.3% by weight of a vanadium compound in terms of V based on TiO 2 weight of titanium oxide, and the amount of the vanadium compound carried per 1 m 2 of the surface area of the titanium oxide particles. Was 58.3 μg in terms of V.
[0014]
Example 4
10 g of the titanium oxide of the sample 1 was immersed in an aqueous solution in which 6.89 mg of ammonium vanadate (NH 4 VO 3 ) was dissolved, then evaporated to dryness, and further dried at a temperature of 110 ° C. The titanium oxide photocatalyst containing the vanadium compound (sample D) was obtained. This sample D contains 0.03% by weight of the vanadium compound in terms of V based on the weight of TiO 2 of titanium oxide, and the amount of the vanadium compound carried per 1 m 2 of the surface area of the titanium oxide particles. Was 5.83 μg in terms of V standard.
[0015]
Example 5
Sample D obtained in Example 4 was calcined at a temperature of 200 ° C. for 3 hours to obtain a titanium oxide photocatalyst containing the vanadium compound of the present invention (Sample E). This sample E contained 0.03% by weight of a vanadium compound in terms of V based on TiO 2 by weight of titanium oxide.
[0016]
Example 6
Sample D obtained in Example 4 was fired at a temperature of 300 ° C. for 3 hours to obtain a titanium oxide photocatalyst containing the vanadium compound of the present invention (Sample F). This sample F contained 0.03% by weight of the vanadium compound in terms of V based on the weight of TiO 2 of titanium oxide.
[0017]
Example 7
Sample D obtained in Example 4 was fired at a temperature of 500 ° C. for 3 hours to obtain a titanium oxide photocatalyst containing the vanadium compound of the present invention (Sample G). This sample G contained 0.03% by weight of a vanadium compound in terms of V based on TiO 2 by weight of titanium oxide.
[0018]
Comparative Example 1
The titanium oxide of Sample 1 obtained in Example 1 was used as Comparative Sample H.
[0019]
The photocatalytic functions of the samples (A to H) obtained in Examples and Comparative Examples were examined as follows. Each sample 0.1g is dispersed in pure water to obtain a suspension of 4g / l in terms of TiO 2. After 25 μl of 2-propanol was added to 25 ml of these suspensions, black light (peak wavelength 365 nm) was irradiated for 2 hours to perform a photocatalytic reaction of 2-propanol. The light amount was 2 mW / cm 2 . The decomposition rate of each sample was calculated from the concentration of 2-propanol before the reaction and the concentration of 2-propanol after the reaction. Table 1 shows the results. As is clear from this table, the titanium oxide photocatalyst of the present invention was found to be excellent in photocatalytic function. Further, the titanium oxide photocatalyst of the present invention can be used for a photocatalytic reaction at a high temperature because the photocatalytic function is hardly deteriorated by heat, and the titanium oxide photocatalyst of the present invention is heated and adhered to a support. be able to.
[0020]
[Table 1]
【The invention's effect】
The titanium oxide photocatalyst of the present invention contains titanium oxide and a vanadium compound, and the photocatalytic function of titanium oxide can be improved by containing a vanadium compound. In particular, when a vanadium compound is supported on the surface of titanium oxide particles, the photocatalytic function of titanium oxide can be further improved. By utilizing the photocatalytic function of the photocatalyst of the present invention, substances that adversely affect the human body and living environment and substances that may have such a possibility can be quickly and efficiently removed, so that not only for industrial use but also for general household use It is extremely useful as a deodorant, a sterilizer, etc. Further, the titanium oxide photocatalyst of the present invention has high safety and does not pollute the environment even when disposed, so that it can be used for various applications.
Claims (2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09371894A JP3579082B2 (en) | 1994-04-06 | 1994-04-06 | Photocatalyst |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP09371894A JP3579082B2 (en) | 1994-04-06 | 1994-04-06 | Photocatalyst |
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| Publication Number | Publication Date |
|---|---|
| JPH07275704A JPH07275704A (en) | 1995-10-24 |
| JP3579082B2 true JP3579082B2 (en) | 2004-10-20 |
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| JP09371894A Expired - Lifetime JP3579082B2 (en) | 1994-04-06 | 1994-04-06 | Photocatalyst |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| JPH10167727A (en) * | 1995-10-26 | 1998-06-23 | Matsumoto Seiyaku Kogyo Kk | Modified titanium oxide sol, photocatalyst composition and its forming agent |
| JP3916799B2 (en) * | 1999-03-19 | 2007-05-23 | 晃雄 小松 | Metal-supported titanium dioxide photocatalyst and method for mass production thereof |
| JP2001096154A (en) * | 1999-09-29 | 2001-04-10 | Yamada Sangyo Kk | Vanadium oxide/titania hybrid photocatalyst and its manufacturing method |
| CN1655869A (en) | 2002-03-25 | 2005-08-17 | 住友钛株式会社 | Titanium oxide-based photocatalyst, manufacturing method therefor and its application |
| JP2004043282A (en) * | 2002-05-20 | 2004-02-12 | Sumitomo Chem Co Ltd | Method of manufacturing titanium oxide |
| CN100375649C (en) * | 2005-12-27 | 2008-03-19 | 中国科学院上海硅酸盐研究所 | Method for preparing kernel-shell structure, visible light catalysis activity type nanometer composite material |
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1994
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