JP2013154333A - Method and apparatus for producing hydrogen and oxygen by decomposing water with photocatalyst - Google Patents
Method and apparatus for producing hydrogen and oxygen by decomposing water with photocatalyst Download PDFInfo
- Publication number
- JP2013154333A JP2013154333A JP2012019356A JP2012019356A JP2013154333A JP 2013154333 A JP2013154333 A JP 2013154333A JP 2012019356 A JP2012019356 A JP 2012019356A JP 2012019356 A JP2012019356 A JP 2012019356A JP 2013154333 A JP2013154333 A JP 2013154333A
- Authority
- JP
- Japan
- Prior art keywords
- photocatalyst
- oxygen
- water
- hydrogen
- ions
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000011941 photocatalyst Substances 0.000 title claims abstract description 85
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 title claims abstract description 67
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 title claims abstract description 47
- 239000001301 oxygen Substances 0.000 title claims abstract description 47
- 229910052760 oxygen Inorganic materials 0.000 title claims abstract description 47
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 title claims abstract description 42
- 238000000034 method Methods 0.000 title claims abstract description 40
- 239000001257 hydrogen Substances 0.000 title claims abstract description 38
- 229910052739 hydrogen Inorganic materials 0.000 title claims abstract description 38
- 238000004519 manufacturing process Methods 0.000 claims abstract description 17
- 230000001678 irradiating effect Effects 0.000 claims abstract description 7
- 229910003071 TaON Inorganic materials 0.000 claims abstract 3
- 150000002500 ions Chemical class 0.000 claims description 29
- 239000007900 aqueous suspension Substances 0.000 claims description 19
- 239000000843 powder Substances 0.000 claims description 14
- 239000007864 aqueous solution Substances 0.000 claims description 11
- 239000007789 gas Substances 0.000 claims description 11
- 229910000001 cobalt(II) carbonate Inorganic materials 0.000 claims description 10
- XLJKHNWPARRRJB-UHFFFAOYSA-N cobalt(2+) Chemical class [Co+2] XLJKHNWPARRRJB-UHFFFAOYSA-N 0.000 claims description 9
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 8
- 239000011248 coating agent Substances 0.000 claims description 8
- 238000000576 coating method Methods 0.000 claims description 8
- 229910001882 dioxygen Inorganic materials 0.000 claims description 8
- 239000006185 dispersion Substances 0.000 claims description 8
- 238000000354 decomposition reaction Methods 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 150000004677 hydrates Chemical class 0.000 claims description 3
- 238000011084 recovery Methods 0.000 claims description 3
- 230000002349 favourable effect Effects 0.000 abstract 2
- 150000003841 chloride salts Chemical class 0.000 abstract 1
- 150000002823 nitrates Chemical class 0.000 abstract 1
- 230000000052 comparative effect Effects 0.000 description 27
- 239000002245 particle Substances 0.000 description 18
- 239000003054 catalyst Substances 0.000 description 15
- 238000006243 chemical reaction Methods 0.000 description 12
- 230000001699 photocatalysis Effects 0.000 description 12
- 239000004065 semiconductor Substances 0.000 description 10
- 239000000243 solution Substances 0.000 description 10
- 241000894007 species Species 0.000 description 10
- 239000000126 substance Substances 0.000 description 9
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical group [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 8
- 239000010419 fine particle Substances 0.000 description 7
- 238000010304 firing Methods 0.000 description 7
- 238000007254 oxidation reaction Methods 0.000 description 7
- 230000008569 process Effects 0.000 description 7
- 238000003756 stirring Methods 0.000 description 7
- 239000008367 deionised water Substances 0.000 description 6
- 229910021641 deionized water Inorganic materials 0.000 description 6
- 238000002360 preparation method Methods 0.000 description 6
- 239000010453 quartz Substances 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 239000000725 suspension Substances 0.000 description 6
- 239000000758 substrate Substances 0.000 description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 229910052786 argon Inorganic materials 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 239000003426 co-catalyst Substances 0.000 description 4
- -1 cobalt (II) salts Chemical class 0.000 description 4
- GVPFVAHMJGGAJG-UHFFFAOYSA-L cobalt dichloride Chemical compound [Cl-].[Cl-].[Co+2] GVPFVAHMJGGAJG-UHFFFAOYSA-L 0.000 description 4
- UFMZWBIQTDUYBN-UHFFFAOYSA-N cobalt dinitrate Chemical compound [Co+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O UFMZWBIQTDUYBN-UHFFFAOYSA-N 0.000 description 4
- 239000011521 glass Substances 0.000 description 4
- 238000005470 impregnation Methods 0.000 description 4
- MRELNEQAGSRDBK-UHFFFAOYSA-N lanthanum(3+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[La+3].[La+3] MRELNEQAGSRDBK-UHFFFAOYSA-N 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 4
- 229910052709 silver Inorganic materials 0.000 description 4
- 239000004332 silver Substances 0.000 description 4
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 4
- 238000003860 storage Methods 0.000 description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-UHFFFAOYSA-N 0.000 description 3
- 229910021607 Silver chloride Inorganic materials 0.000 description 3
- 230000003197 catalytic effect Effects 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000001035 drying Methods 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000013032 photocatalytic reaction Methods 0.000 description 3
- HKZLPVFGJNLROG-UHFFFAOYSA-M silver monochloride Chemical compound [Cl-].[Ag+] HKZLPVFGJNLROG-UHFFFAOYSA-M 0.000 description 3
- 229910052724 xenon Inorganic materials 0.000 description 3
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 3
- RZVAJINKPMORJF-UHFFFAOYSA-N Acetaminophen Chemical compound CC(=O)NC1=CC=C(O)C=C1 RZVAJINKPMORJF-UHFFFAOYSA-N 0.000 description 2
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 101710134784 Agnoprotein Proteins 0.000 description 2
- 229910021193 La 2 O 3 Inorganic materials 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 239000012327 Ruthenium complex Substances 0.000 description 2
- 229910010413 TiO 2 Inorganic materials 0.000 description 2
- 229910021529 ammonia Inorganic materials 0.000 description 2
- 239000012159 carrier gas Substances 0.000 description 2
- 239000000084 colloidal system Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007613 environmental effect Effects 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 229910021645 metal ion Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000003002 pH adjusting agent Substances 0.000 description 2
- 229910052697 platinum Inorganic materials 0.000 description 2
- 239000005297 pyrex Substances 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- 229910001961 silver nitrate Inorganic materials 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 2
- CMPGARWFYBADJI-UHFFFAOYSA-L tungstic acid Chemical compound O[W](O)(=O)=O CMPGARWFYBADJI-UHFFFAOYSA-L 0.000 description 2
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 1
- QWMFKVNJIYNWII-UHFFFAOYSA-N 5-bromo-2-(2,5-dimethylpyrrol-1-yl)pyridine Chemical compound CC1=CC=C(C)N1C1=CC=C(Br)C=N1 QWMFKVNJIYNWII-UHFFFAOYSA-N 0.000 description 1
- 229910021580 Cobalt(II) chloride Inorganic materials 0.000 description 1
- 241000511976 Hoya Species 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- PMZURENOXWZQFD-UHFFFAOYSA-L Sodium Sulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=O PMZURENOXWZQFD-UHFFFAOYSA-L 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 239000003729 cation exchange resin Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000011437 continuous method Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000009849 deactivation Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- SWXVUIWOUIDPGS-UHFFFAOYSA-N diacetone alcohol Natural products CC(=O)CC(C)(C)O SWXVUIWOUIDPGS-UHFFFAOYSA-N 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 239000008151 electrolyte solution Substances 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 230000033444 hydroxylation Effects 0.000 description 1
- 238000005805 hydroxylation reaction Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- 230000031700 light absorption Effects 0.000 description 1
- 230000000873 masking effect Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000000075 oxide glass Substances 0.000 description 1
- BPUBBGLMJRNUCC-UHFFFAOYSA-N oxygen(2-);tantalum(5+) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ta+5].[Ta+5] BPUBBGLMJRNUCC-UHFFFAOYSA-N 0.000 description 1
- 238000007540 photo-reduction reaction Methods 0.000 description 1
- 238000002256 photodeposition Methods 0.000 description 1
- 238000006303 photolysis reaction Methods 0.000 description 1
- 230000015843 photosynthesis, light reaction Effects 0.000 description 1
- 229940068886 polyethylene glycol 300 Drugs 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000005215 recombination Methods 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 230000001235 sensitizing effect Effects 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 229910052938 sodium sulfate Inorganic materials 0.000 description 1
- 235000011152 sodium sulphate Nutrition 0.000 description 1
- MZLGASXMSKOWSE-UHFFFAOYSA-N tantalum nitride Chemical compound [Ta]#N MZLGASXMSKOWSE-UHFFFAOYSA-N 0.000 description 1
- 229910001936 tantalum oxide Inorganic materials 0.000 description 1
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten trioxide Chemical compound O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
Landscapes
- Catalysts (AREA)
Abstract
Description
本発明は、光触媒により水を分解して水素及び酸素を製造する方法及び装置に関する。 The present invention relates to a method and apparatus for producing hydrogen and oxygen by decomposing water with a photocatalyst.
近年、省エネルギーおよび環境保全等の観点から、太陽光などの光エネルギーを用いて光触媒反応により水を分解して水素及び酸素を製造することに関心が集まっている。光触媒を利用した水の分解反応において光触媒（主触媒）の触媒活性を高めるために、助触媒を主触媒に担持する方法が提案されている。助触媒を主触媒に担持することによって、光吸収により生成した電子と正孔が再結合することを防止することができるとともに、活性の高い反応サイト（活性点）を提供することができる。例えば、特許文献１には、担持させるべき金属微粒子（助触媒）を構成する金属のイオンを含む溶液に主触媒を浸漬し、乾燥し、焼成することによって、主触媒に金属微粒子を担持する方法が記載されている。この方法は、一般的に含浸担持法として知られている。特許文献１には、担持させるべき金属微粒子（助触媒）を構成する金属のイオンを含む溶液に主触媒を浸漬し、得られた溶液に、脱酸素しながら光照射することで金属微粒子を担持する方法も記載されている。この方法は、一般的に光電着担持法（光還元析出担持法）として知られている。また、特許文献２には、水の光分解反応により水素及び酸素を製造するための装置として、可視光応答性光触媒とレドックス媒体を含む水素生成セルと半導体電極を有する酸素生成セルと両者を導通する手段とを備えた装置が記載されており、白金を表面に担持した酸化チタン（Ｐｔ−ＴｉＯ2）を、ルテニウム錯体のエタノール溶液中で攪拌し、遠心分離し、乾燥することによってルテニウム錯体が吸着したＰｔ−ＴｉＯ2光触媒を得たことが記載されている。
In recent years, from the viewpoint of energy saving and environmental conservation, there has been an interest in producing hydrogen and oxygen by decomposing water by photocatalytic reaction using light energy such as sunlight. In order to increase the catalytic activity of the photocatalyst (main catalyst) in the water decomposition reaction using the photocatalyst, a method of supporting a cocatalyst on the main catalyst has been proposed. By supporting the cocatalyst on the main catalyst, it is possible to prevent recombination of electrons and holes generated by light absorption and to provide a highly active reaction site (active point). For example, Patent Document 1 discloses a method in which metal fine particles are supported on the main catalyst by immersing the main catalyst in a solution containing metal ions constituting the metal fine particles (co-catalyst) to be supported, drying, and firing. Is described. This method is generally known as an impregnation support method. In Patent Document 1, a main catalyst is immersed in a solution containing metal ions constituting metal fine particles (co-catalyst) to be supported, and the resulting solution is irradiated with light while deoxidizing to support the metal fine particles. A method to do is also described. This method is generally known as a photodeposition support method (photoreduction deposition support method).
しかしながら、上記のように、主触媒に助触媒が担持された光触媒を調製する場合に、触媒の調製のための工程、特に主触媒に助触媒を担持するために行われる撹拌、分離、乾燥、焼成などの工程は、一般的に、複雑な操作を必要とすることに加えて、長い時間と大量のエネルギーを必要とするという欠点がある。また、これらの工程を実施するために使用される設備に高いコストがかかり、商業的設備では各工程で使用される装置が大型になるという欠点がある。さらに、焼成工程により助触媒が凝集することがあり、凝集によって助触媒の分散性が低下するため、主触媒に助触媒を担持したものについての最終的な触媒活性の向上を妨げる一因となっていた。光触媒反応の活性を高めるために、活性点は、できるだけ多く、かつ、できるだけ均一に存在することが望ましい。主触媒に担持させる助触媒の粒径をできるだけ小さくすることによって、活性点の数をできるだけ多くすることができる。しかし、一般的に、粒子間に作用する凝集力は、粒子の粒径が小さいほど強いことが知られている。活性点の数を増やすために、助触媒の粒径をより小さくするほど、助触媒の粒子間に作用する凝集力はますます強くなり、助触媒の粒子が凝集してより大粒径の粒子を形成する傾向が高くなってしまい、その結果、分散性を向上させることが困難になり、光触媒活性を十分に向上させることが難しいという問題がある。 However, as described above, when preparing a photocatalyst having a main catalyst supported on a main catalyst, a step for preparing the catalyst, particularly stirring, separation, drying performed to support the main catalyst on the main catalyst, In general, a process such as firing has a drawback that it requires a long time and a large amount of energy in addition to a complicated operation. In addition, the equipment used to carry out these processes is expensive, and the commercial equipment has the disadvantage that the equipment used in each process is large. In addition, the co-catalyst may be agglomerated by the calcination process, and the dispersibility of the co-catalyst decreases due to the agglomeration. It was. In order to increase the activity of the photocatalytic reaction, it is desirable that the active sites exist as many as possible and as uniformly as possible. By making the particle size of the promoter supported on the main catalyst as small as possible, the number of active sites can be increased as much as possible. However, it is generally known that the cohesive force acting between particles is stronger as the particle size of the particles is smaller. The smaller the cocatalyst particle size is to increase the number of active sites, the stronger the cohesive force acting between the cocatalyst particles, and the cocatalyst particles agglomerate to form larger particles. As a result, it becomes difficult to improve the dispersibility, and it is difficult to sufficiently improve the photocatalytic activity.
従って、本発明は、光触媒を使用して、簡便な操作及び装置で、低コストで酸素及び水素を高収率で製造することができる水の分解方法及び装置を提供することを目的とする。 Therefore, an object of the present invention is to provide a method and an apparatus for decomposing water that can produce oxygen and hydrogen in high yield at a low cost with a simple operation and apparatus using a photocatalyst.
本発明は、上記課題を解決すべく鋭意研究を重ねた結果、光触媒により分解させる水中にＣｏ2+イオンを含めることによって、助触媒を必要とせずに、簡便な操作で、低コストで、高収率で水を光触媒的に分解できることを見出し、本発明を完成するに至った。 As a result of intensive studies to solve the above-mentioned problems, the present invention includes Co 2+ ions in water to be decomposed by a photocatalyst, so that no cocatalyst is required, simple operation, low cost, and high cost. It was found that water can be photocatalytically decomposed in a yield, and the present invention has been completed.
本発明によれば、光触媒により水を分解して水素及び酸素を製造する方法であって、
光触媒及びＣｏ2+イオンを含む水を用意する工程、及び
光触媒に光を照射して水を水素及び酸素に分解する工程、
を含むことを特徴とする方法が提供される。
According to the present invention, a method for producing hydrogen and oxygen by decomposing water with a photocatalyst,
A step of preparing water containing photocatalyst and Co 2+ ions, and a step of irradiating the photocatalyst with light to decompose water into hydrogen and oxygen,
Is provided.
本発明によれば、さらに、
光触媒及びＣｏ2+イオンを含む水を導入して光触媒により水を分解させるための反応器と、
光触媒による水の分解反応により生成した酸素ガス及び水素ガスを回収するためのガス回収装置と、
を含む装置が提供される。
According to the invention,
A reactor for introducing water containing photocatalyst and Co 2+ ions and decomposing water by the photocatalyst;
A gas recovery device for recovering oxygen gas and hydrogen gas generated by water decomposition reaction by a photocatalyst;
A device is provided.
本発明によれば、簡便な操作及び装置で、低コストで、酸素及び水素を高収率で製造することができる。 According to the present invention, oxygen and hydrogen can be produced in a high yield at a low cost with a simple operation and apparatus.
本発明の方法において使用される光触媒は、太陽光または人工光源からの光（可視から紫外領域の波長の光を含む）に照射されることにより光触媒活性を示す物質であればよく、特に制限されない。光触媒は、化学的安定性及び光触媒活性から、酸化物半導体光触媒であることが好ましい。酸化物半導体光触媒は公知の方法により製造することができる。酸化物半導体光触媒の例としては、タンタルオキシナイトライド（ＴａＯＮ）、酸化タングステン（ＷＯ3 ）などが挙げられる。酸化物半導体光触媒は、照射する光の照射下で光触媒活性を示すように、照射する光の波長に応じて、増感色素により増感されたものであっても、他元素をドープしたものであってもよい。本発明の方法において使用される光触媒は、１種又は２種以上の酸化物半導体触媒から構成することができる。可視から紫外領域の波長の光に照射されることにより高い触媒活性を示すことから、ＴａＯＮ及びＷＯ3が好ましい。 The photocatalyst used in the method of the present invention is not particularly limited as long as it is a substance that exhibits photocatalytic activity when irradiated with sunlight or light from an artificial light source (including light having a wavelength in the visible to ultraviolet region). . The photocatalyst is preferably an oxide semiconductor photocatalyst from the viewpoint of chemical stability and photocatalytic activity. The oxide semiconductor photocatalyst can be produced by a known method. Examples of the oxide semiconductor photocatalyst include tantalum oxynitride (TaON), tungsten oxide (WO 3 ), and the like. Oxide semiconductor photocatalysts are doped with other elements, even if they are sensitized with a sensitizing dye, depending on the wavelength of the irradiated light, so as to exhibit photocatalytic activity under irradiation of the irradiated light. There may be. The photocatalyst used in the method of the present invention can be composed of one or more oxide semiconductor catalysts. TaON and WO 3 are preferred because they exhibit high catalytic activity when irradiated with light having a wavelength in the visible to ultraviolet region.
光触媒は、水性懸濁液もしくは水性分散液の形態で使用するか、あるいは、粉末、コーティング、成形体などの形態で使用できる。そのため、本発明において、水素及び酸素を製造するために使用される反応装置のタイプに応じて、種々の光触媒を使用できる。 The photocatalyst can be used in the form of an aqueous suspension or aqueous dispersion, or can be used in the form of a powder, a coating, a molded body, or the like. Therefore, in the present invention, various photocatalysts can be used depending on the type of reaction apparatus used for producing hydrogen and oxygen.
本発明の方法において、Ｃｏ2+イオンは、水に溶解してＣｏ2+イオンを生成することのできるＣｏ2+イオン源、典型的には、水溶性のコバルト（ＩＩ）塩から誘導することができる。コバルト（ＩＩ）塩の例としては、Ｃｏ（ＮＯ3）2、ＣｏＣｌ2及びその水和物が挙げられる。 In the method of the present invention, Co 2+ ions, Co 2+ ion source capable of producing a Co 2+ ions dissolved in water, it is typically derived from a water-soluble cobalt (II) salt Can do. Examples of cobalt (II) salts include Co (NO 3 ) 2 , CoCl 2 and hydrates thereof.
本発明の水素及び酸素の製造方法において、光触媒及びＣｏ2+イオンを含む水を用意する工程は、例えば、水に光触媒及びＣｏ2+イオン源（例えば固体（粉末状、顆粒状など）のコバルト（ＩＩ）塩）を加えて撹拌しＣｏ2+イオン源を水に溶解させるとともに光触媒を水中に分散させるか、光触媒を含む水性懸濁液又は水性分散液（予め調製されたもの）にＣｏ2+イオン源（例えば固体（粉末状、顆粒状など）のコバルト（ＩＩ）塩）を溶解させるか、光触媒を含む水性懸濁液又は水性分散液（予め調製された）にＣｏ2+イオン源（例えばコバルト（ＩＩ）塩）の水溶液を加えるか、または、粉末状、コーティング又は成形体の形態の光触媒とＣｏ2+イオン源（例えばコバルト（ＩＩ）塩）の水溶液とを組み合わせることにより実施できるが、これらに限定されない。 In the method for producing hydrogen and oxygen of the present invention, the step of preparing water containing a photocatalyst and Co 2+ ions is, for example, a photocatalyst and a Co 2+ ion source (eg, solid (powder, granular, etc.) cobalt in water). (II) salt) is added and stirred to dissolve the Co 2+ ion source in water and the photocatalyst is dispersed in water, or Co 2 is added to an aqueous suspension or aqueous dispersion (prepared) containing the photocatalyst. + Co 2+ ion source (for example, a solid (powder, granular, etc.) cobalt (II) salt) dissolved in an aqueous suspension or dispersion (previously prepared) containing a photocatalyst for example either adding an aqueous solution of cobalt (II) salts), or powder, it can be carried out by combining an aqueous solution of the coating or the molded body in the form of a photocatalyst and Co 2+ ion source (for example, cobalt (II) salt) But it is not limited to these.
本発明の水素及び酸素の製造方法において、光触媒に光を照射することにより電子と正孔が生成し、生成した電子は水を水素（Ｈ2）に還元する。一方、生成した正孔によりＣｏ2+イオンはＣｏ3+イオンに酸化され、生成したＣｏ3+イオンは次に水を酸化して酸素（Ｏ2）を生成する。このように、加えられたＣｏ2+イオンは、光触媒を含む水中でＣｏ2+／Ｃｏ3+酸化還元対を形成する。上記のサイクルが繰り返されることで、水が水素と酸素に連続的に分解される。本発明では、形成されたＣｏ2+／Ｃｏ3+酸化還元対が水中に溶解した状態で存在するため、助触媒が担持された光触媒を使用する場合と比べて、より均一な光触媒反応系を実現することができる。コバルト（ＩＩ）塩の対アニオンの他に、反応を妨げない限り、任意の種類のイオンが存在してもよい。本発明において使用される触媒は、助触媒を担持せずに調製できるため、従来技術による助触媒を担持した光触媒を調製する際に必要とされていた複雑な操作や設備が不要であり、コストも大幅に改善できる。 In the method for producing hydrogen and oxygen of the present invention, electrons and holes are generated by irradiating light to the photocatalyst, and the generated electrons reduce water to hydrogen (H 2 ). On the other hand, Co 2+ ions are oxidized to Co 3+ ions by the generated holes, and the generated Co 3+ ions then oxidize water to generate oxygen (O 2 ). Thus, the added Co 2+ ions form a Co 2+ / Co 3+ redox pair in water containing the photocatalyst. By repeating the above cycle, water is continuously decomposed into hydrogen and oxygen. In the present invention, since the formed Co 2+ / Co 3+ redox couple is present in a dissolved state in water, a more uniform photocatalytic reaction system can be obtained compared to the case of using a photocatalyst carrying a promoter. Can be realized. In addition to the counter anion of the cobalt (II) salt, any type of ion may be present as long as it does not interfere with the reaction. Since the catalyst used in the present invention can be prepared without supporting a cocatalyst, the complicated operation and equipment required for preparing the photocatalyst supporting the cocatalyst according to the prior art are unnecessary, and the cost is reduced. Can be greatly improved.
本発明の水素及び酸素の製造方法は、連続式、バッチ式などのいずれの方式でも実施でき、水素及び酸素を製造するために使用される反応装置の触媒充填方式としては、流動床型、撹拌槽型、固定床型反応装置などの各種の反応装置を使用できる。 The method for producing hydrogen and oxygen of the present invention can be carried out by any method such as a continuous method and a batch method, and the catalyst filling method of the reactor used for producing hydrogen and oxygen includes a fluidized bed type, a stirring method, and the like. Various reactors such as a tank type and a fixed bed type reactor can be used.
例えば、本発明の水素及び酸素の製造方法を流動床型反応装置又は撹拌槽型反応装置を使用して実施する場合に、光触媒を水性懸濁液もしくは水性分散液の形態で使用することができる。 For example, when the method for producing hydrogen and oxygen of the present invention is carried out using a fluidized bed reactor or a stirred tank reactor, the photocatalyst can be used in the form of an aqueous suspension or aqueous dispersion. .
本発明の方法を固定床型反応装置を使用して実施する場合に、例えば、反応器に粒子状の光触媒を充填するか、あるいは、反応器壁の水と接触している側の少なくとも一部に光触媒をコーティングすることによって、反応器に光触媒を充填することができる。 When the method of the invention is carried out using a fixed bed reactor, for example, the reactor is filled with particulate photocatalyst or at least part of the side of the reactor wall in contact with water The reactor can be filled with a photocatalyst by coating with a photocatalyst.
流動床型、撹拌槽型、固定床型反応装置などのいずれのタイプの反応装置を使用する場合でも、反応器は、反応器壁の少なくとも一部が光触媒に照射する光に対して透明であるものであることができ、当該透明な部分を通して太陽光又は反応器の外側に設置された光源からの光を光触媒に照射することができる。反応器の外側から光を照射しながら、光触媒及びＣｏ2+イオンを含む水を、反応器内で、例えば連続式またはバッチ式で、水素と酸素に分解することができる。太陽光又は反応器の外側に設置された人工光源からの光を、光導波路を通して反応器内の光触媒に案内することができる。反応器の内側に人工光源が設置されていてもよく、反応装置の外側に設置された人工光源を使用してもよい。光触媒に照射する光は、太陽光であっても、人工光源から放出された光であってもよいが、省エネルギー及び環境保全等の観点から、太陽光であることが望ましい。人工光源を使用する場合には、光触媒の触媒活性の点から、人工光源は可視から紫外領域の波長を有する光を放出するものであることが好ましい。 Regardless of the type of reactor such as fluidized bed type, stirred tank type, fixed bed type reactor, etc., the reactor is transparent to the light that at least part of the reactor wall irradiates the photocatalyst. The photocatalyst can be irradiated with sunlight or light from a light source installed outside the reactor through the transparent portion. While irradiating light from the outside of the reactor, the water containing the photocatalyst and Co 2+ ions can be decomposed into hydrogen and oxygen in the reactor, for example, continuously or batchwise. Sunlight or light from an artificial light source installed outside the reactor can be guided to the photocatalyst in the reactor through an optical waveguide. An artificial light source may be installed inside the reactor, or an artificial light source installed outside the reactor may be used. The light applied to the photocatalyst may be sunlight or light emitted from an artificial light source, but is preferably sunlight from the viewpoint of energy saving and environmental protection. When an artificial light source is used, it is preferable that the artificial light source emits light having a wavelength in the visible to ultraviolet region from the viewpoint of the catalytic activity of the photocatalyst.
本発明において、光触媒は、上記のような形態の他に、例えば、当該技術分野で周知の方法を使用して、基材（例えば、無孔質又は多孔質の無機又は有機材料、例えば、ＷＯ3、などの材料から形成された基材）にコーティングすることにより得られた被覆基材、あるいは、当該技術分野で周知の方法を使用して、光触媒を所望の形状に成形することにより得られた成形体を、例えば光電極として使用し、水を光触媒的に分解させることもできる。光触媒を、電極基材上にコーティングするか又は光触媒を成形することによって、光電極を製造することができる。本発明では、光触媒の微粒子をそのまま水中に懸濁させて利用する場合と、導電性基板などの上に固定化して「（水酸化用）光電極」として利用する場合の両方に応用可能であり、特に水を酸化して酸素を生成する過程を促進・効率化する点に特徴を有する（Ｃｏ2+種の添加により著しく促進される）。
光触媒の水性懸濁液は、光触媒の微粒子をマグネチックスターラーや撹拌装置などを用いて水に懸濁させることにより得ることができる。また、光触媒を光電極として利用する場合には、硫酸ナトリウムなどの電解質を加えた水溶液中に、酸素を発生する「光電極」と水素を発生する「対極」を固定化し、「光電極」側に光を照射し、また両極間に適切な外部バイアス（電圧）を印加して反応を行うことができる。この際に用いる「対極」は主に白金やニッケルなどの水素生成過電圧が低い材料を用いることができる。また、「対極」の代わりに、別の半導体材料を固定化した「水還元用光電極」を用いて、上記の「水酸化用光電極」と接続させ、両方に光照射を行って水を分解することもでき、適切な組み合わせを用いることにより反応に必要な外部バイアスを大幅に低減（もしくは無しに）できる可能性を有する。
本発明によれば、通常は起こりにくい「水の酸化反応」を極めて単純な手法（Ｃｏ2+種の添加）によって促進できる。
In the present invention, the photocatalyst is used in addition to the above-described form, for example, using a method well known in the art, for example, a nonporous or porous inorganic or organic material such as WO 3. A coated substrate obtained by coating a substrate formed from a material such as, or a photocatalyst is formed into a desired shape using a method well known in the art. The molded body can be used as, for example, a photoelectrode to decompose water in a photocatalytic manner. A photoelectrode can be produced by coating a photocatalyst on an electrode substrate or molding the photocatalyst. The present invention is applicable to both the case where the photocatalyst fine particles are suspended in water as they are and the case where the photocatalyst fine particles are immobilized on a conductive substrate or the like and used as a “(hydroxylation) photoelectrode”. In particular, it is characterized in that the process of generating oxygen by oxidizing water is promoted and made efficient (remarkably promoted by the addition of Co 2+ species).
An aqueous suspension of the photocatalyst can be obtained by suspending the fine particles of the photocatalyst in water using a magnetic stirrer or a stirring device. When using a photocatalyst as a photoelectrode, the “photoelectrode” that generates oxygen and the “counter electrode” that generates hydrogen are fixed in an aqueous solution to which an electrolyte such as sodium sulfate is added. The reaction can be carried out by irradiating with light and applying an appropriate external bias (voltage) between the two electrodes. As the “counter electrode” used in this case, a material having a low hydrogen overvoltage such as platinum or nickel can be mainly used. In addition, instead of the “counter electrode”, a “water reduction photoelectrode” in which another semiconductor material is immobilized is connected to the above “hydration photoelectrode” and light is irradiated to both to irradiate water. It can also be decomposed and has the potential to significantly reduce (or eliminate) the external bias required for the reaction by using appropriate combinations.
According to the present invention, the “water oxidation reaction” that is unlikely to occur normally can be promoted by a very simple method (addition of Co 2+ species).
本発明に係る水素及び酸素の製造装置において、水の分解反応により生成した酸素ガス及び水素ガスを、酸素ガスと水素ガスの混合ガスとして、反応器のガス排出口に接続されたガス回収装置（例えばガス排出管など）により回収することができる。ガス排出装置は、本発明に係る水素及び酸素の製造装置の内部又は外部に設置された酸素ガスと水素ガスを分離する分離装置に接続されていてもよい。分離した酸素ガスと水素ガスを、それぞれ、酸素貯蔵装置及び水素貯蔵装置に貯蔵することができる。かかる酸素貯蔵装置及び水素貯蔵装置は、本発明に係る水素及び酸素の製造装置の内部又は外部に設置することができる。さらに、本発明に係る水素及び酸素の製造装置は、分解反応により消費された水を補充するために、反応器に水を補充するための水供給装置を備えていてもよい。 In the hydrogen and oxygen production apparatus according to the present invention, a gas recovery apparatus (as a mixed gas of oxygen gas and hydrogen gas) produced by the water decomposition reaction and connected to the gas outlet of the reactor ( For example, it can be recovered by a gas discharge pipe or the like. The gas discharge device may be connected to a separation device that separates the oxygen gas and the hydrogen gas installed inside or outside the hydrogen and oxygen production apparatus according to the present invention. The separated oxygen gas and hydrogen gas can be stored in an oxygen storage device and a hydrogen storage device, respectively. Such an oxygen storage device and a hydrogen storage device can be installed inside or outside the hydrogen and oxygen production device according to the present invention. Furthermore, the apparatus for producing hydrogen and oxygen according to the present invention may include a water supply device for replenishing the reactor with water in order to replenish the water consumed by the decomposition reaction.
以下に示す実施例及び比較例を参照して本発明をさらに詳しく説明するが、本発明の技術的な範囲は、これらの実施例によって限定されるものでないことは言うまでもない。 The present invention will be described in more detail with reference to the following examples and comparative examples, but it goes without saying that the technical scope of the present invention is not limited by these examples.
実施例１：Ｃｏ2+イオンを含むＴａＯＮ水性懸濁液の調整
光触媒として、タンタルオキシナイトライド（ＴａＯＮ）を使用した。市販の酸化タンタル粒子（Ｔａ2Ｏ5、高純度化学研究所、９９．９％）１０ｇを石英ボードにつめた後、この石英ボードを石英管（内径４５ｍｍ）内に静置し、石英管内に窒素を流通（１００ｍＬ／ｍｉｎ）させて空気を除去した後に、アンモニアを流通（６０ｍＬ／ｍｉｎ）させ、外部加熱型の電気炉を用いて８５０℃に加熱し、１５時間アンモニアを流通させ続けた。自然冷却後、石英管内を窒素に置換し、石英ボードを取り出して、タンタルナイトライド（Ｔａ3Ｎ5）などの不純物を除去して、ＴａＯＮ粒子を合成した。得られたＴａＯＮの粒径は、０．３〜０．６μｍであった。ＴａＯＮの水性懸濁液は、５０ｍｇのＴａＯＮを２５０ｍＬの脱イオン水に加え、マグネチックスターラーを用いて約１０００ｒｐｍで撹拌して懸濁させた。この懸濁液にさらにｐＨ調整剤として酸化ランタン（Ｌａ2Ｏ3、和光純薬工業株式会社、９９．５％）を０．２ｇ、および電子受容体として硝酸銀（ＡｇＮＯ3、和光純薬工業株式会社、９９．８％）を０．５４ｇ（３．２ｍｍｏｌに相当）加えた。この際、ＴａＯＮの水性懸濁液中に含まれるＴａＯＮの量は脱イオン水１リットルあたり、０．２５ｇであった。
次に、上記のように調製したＴａＯＮの水性懸濁液２５０ｍＬに塩化コバルト（ＩＩ）（ＣｏＣｌ2）を１ｍｇ添加し、撹拌することによって、本発明に従うＣｏ2+イオンを含むＴａＯＮ水性懸濁液（１）を調製した。
Example 1: Preparation of aqueous TaON suspension containing Co 2+ ions Tantalum oxynitride (TaON) was used as a photocatalyst. After putting 10 g of commercially available tantalum oxide particles (Ta 2 O 5 , High Purity Chemical Laboratory, 99.9%) on a quartz board, the quartz board was left standing in a quartz tube (inner diameter 45 mm) and placed in the quartz tube. After nitrogen was circulated (100 mL / min) to remove air, ammonia was circulated (60 mL / min), heated to 850 ° C. using an external heating type electric furnace, and ammonia was continuously circulated for 15 hours. After natural cooling, the inside of the quartz tube was replaced with nitrogen, the quartz board was taken out, impurities such as tantalum nitride (Ta 3 N 5 ) were removed, and TaON particles were synthesized. The particle size of the obtained TaON was 0.3 to 0.6 μm. The aqueous suspension of TaON was suspended by adding 50 mg of TaON to 250 mL of deionized water and stirring at about 1000 rpm using a magnetic stirrer. Further, 0.2 g of lanthanum oxide (La 2 O 3 , Wako Pure Chemical Industries, Ltd., 99.5%) as a pH adjuster and silver nitrate (AgNO 3 , Wako Pure Chemical Industries, Ltd.) as an electron acceptor are added to the suspension. Company, 99.8%) was added at 0.54 g (corresponding to 3.2 mmol). At this time, the amount of TaON contained in the aqueous suspension of TaON was 0.25 g per liter of deionized water.
Next, 1 mg of cobalt chloride (II) (CoCl 2 ) is added to 250 mL of the aqueous suspension of TaON prepared as described above, and stirred to obtain an aqueous TaON suspension containing Co 2+ ions according to the present invention. (1) was prepared.
実施例２：Ｃｏ2+イオンを含むＴａＯＮ水性懸濁液の調製
上記のように調製したＴａＯＮの水性懸濁液２５０ｍＬに硝酸コバルト（ＩＩ）（Ｃｏ（ＮＯ3）2）を１．２３ｍｇ添加し、撹拌することによって、本発明に従うＣｏ2+イオンを含むＴａＯＮ水性懸濁液（２）を調製した。
Example 2: Preparation of TaON aqueous suspension containing Co 2+ ions 1.23 mg of cobalt (II) nitrate (Co (NO 3 ) 2 ) was added to 250 mL of the aqueous TaON suspension prepared as described above. An aqueous TaON suspension (2) containing Co 2+ ions according to the present invention was prepared by stirring.
比較例１〜４：光触媒粉末の調製
比較例１〜４の光触媒粉末を以下のように調製した。
（１）比較例１の光触媒：
実施例１に記された手法にて合成したＴａＯＮ粒子０．１ｇと脱イオン水１０ｍＬを磁性蒸発皿に加え、さらに１０ｍＭ−ＣｏＣｌ2水溶液０．８５ｍＬ（ＴａＯＮに対して、Ｃｏ換算で０．５ｗｔ％相当）を加え、超音波洗浄機を用いてＴａＯＮ粒子をよく分散させた。この蒸発皿を湯浴によって加熱し、ガラス棒を用いて撹拌しながら水分を蒸発させた。その後、この粉末を含む蒸発皿を卓上マッフル炉（株式会社デンケン、ＫＤＦ−Ｓ７０）中において、空気雰囲気下、３００℃で１時間加熱焼成を行うことにより、ＴａＯＮにＣｏＣｌ2を含浸担持させた光触媒（ＣｏＣｌ2含浸担持３００℃）粉末を調製した。
（２）比較例２の光触媒：
空気雰囲気下における焼成時の温度を３００℃から１００℃に変更した以外は、比較例１と同様の手法を用いて、ＴａＯＮにＣｏＣｌ2を含浸担持させた光触媒（ＣｏＣｌ2含浸担持１００℃）粉末を調製した。
（３）比較例３の光触媒：
１ｍＭのＣｏＣｌ2水溶液ｍＬの代わりに１０ｍＭのＣｏ（ＮＯ3）2水溶液を用いた以外は、比較例１と同様の手法を用いて、ＴａＯＮにＣｏ（ＮＯ3）2を含浸担持させた光触媒（Ｃｏ（ＮＯ3）2含浸担持３００℃）粒子を調製した。
（４）比較例４の光触媒：
空気雰囲気下における焼成時の温度を３００℃から１００℃に変更した以外は、比較例３と同様の手法を用いて、ＴａＯＮにＣｏ（ＮＯ3）2を含浸担持させた光触媒（Ｃｏ（ＮＯ3）2含浸担持１００℃）粒子を調製した。
Comparative Examples 1 to 4: Preparation of Photocatalyst Powder The photocatalyst powders of Comparative Examples 1 to 4 were prepared as follows.
(1) Photocatalyst of Comparative Example 1:
0.1 g of TaON particles synthesized by the method described in Example 1 and 10 mL of deionized water were added to a magnetic evaporating dish, and further 0.85 mL of 10 mM-CoCl 2 aqueous solution (0.5 wt in terms of Co with respect to TaON). % Equivalent) and TaON particles were well dispersed using an ultrasonic cleaner. This evaporating dish was heated with a hot water bath, and water was evaporated while stirring using a glass rod. Thereafter, the evaporating dish containing this powder was baked for 1 hour at 300 ° C. in an air atmosphere in a desktop muffle furnace (Denken Co., Ltd., KDF-S70) to impregnate and support CoCl 2 on TaON. (CoCl 2 impregnation supported 300 ° C.) powder was prepared.
(2) Photocatalyst of Comparative Example 2:
Photocatalyst (CoCl 2 impregnated support 100 ° C.) powder in which TaON is impregnated and supported with CoCl 2 using the same method as in Comparative Example 1, except that the temperature at the time of firing in an air atmosphere is changed from 300 ° C. to 100 ° C. Was prepared.
(3) Photocatalyst of Comparative Example 3:
A photocatalyst prepared by impregnating and supporting Co (NO 3 ) 2 on TaON using the same method as in Comparative Example 1 except that 10 mM Co (NO 3 ) 2 aqueous solution was used instead of 1 mM CoCl 2 aqueous solution mL. Co (NO 3 ) 2 impregnation supported 300 ° C. particles were prepared.
(4) Photocatalyst of Comparative Example 4:
A photocatalyst (Co (NO 3 ) obtained by impregnating and supporting Co (NO 3 ) 2 on TaON was used in the same manner as in Comparative Example 3 except that the temperature during firing in an air atmosphere was changed from 300 ° C. to 100 ° C. 2 ) Impregnated supported 100 ° C.) particles were prepared.
光触媒活性の評価
本発明に従うＣｏ2+イオンを含むＴａＯＮ水性懸濁液（１）および（２）について、それぞれ以下のようにして光触媒活性を評価した。
内容積３５０ｍＬの透明ガラス（パイレックス（登録商標）製反応容器に、Ｃｏ2+イオンを含むＴａＯＮの水性懸濁液（１）または（２）を２５０ｍＬ入れ、反応容器を閉鎖循環ラインに接続し、この系内をアルゴンガスで置換した。反応容器を１５℃に設定した恒温槽内の純水中に沈めた。光源として、カットオフフィルター（ＨＯＹＡ製、Ｌ−４２）を装着した３００Ｗキセノンランプ（Ｃｅｒｍａｘ社製）を用い、波長４００ｎｍ以上の可視光のみ照射させた。反応容器内の水性懸濁液に照射して、ＴａＯＮ半導体粒子内に生成した励起電子によって銀イオン（Ａｇ+）を還元させるとともに、正孔によって水を酸化させて酸素を発生させた。光照射によって発生した酸素の量をガスクロマトグラフ（島津製、カラム：ＭＳ−５Ａ）を使用して追跡することにより、水の光触媒的酸化反応を追跡した。キャリアガスとしてアルゴンを使用し、流量を４０ｍＬ／ｍｉｎとした。
Evaluation of Photocatalytic Activity The TaON aqueous suspensions (1) and (2) containing Co 2+ ions according to the present invention were evaluated for photocatalytic activity as follows.
An inner volume of 350 mL of transparent glass (Pyrex (registered trademark) reaction vessel containing 250 mL of TaON aqueous suspension (1) or (2) containing Co 2+ ions) was connected to the closed circulation line, The inside of this system was replaced with argon gas, and the reaction vessel was submerged in pure water in a thermostatic bath set at 15 ° C. A 300 W xenon lamp equipped with a cutoff filter (manufactured by HOYA, L-42) as a light source ( Irradiated only to visible light having a wavelength of 400 nm or more using a Cermax Co., Ltd. Irradiated to an aqueous suspension in a reaction vessel to reduce silver ions (Ag + ) by excited electrons generated in TaON semiconductor particles. At the same time, water was oxidized by holes to generate oxygen, and the amount of oxygen generated by light irradiation was measured using a gas chromatograph (manufactured by Shimadzu, column: MS-5A). By tracking and use were followed photocatalytic oxidation of water. Argon was used as a carrier gas, the flow rate was 40 mL / min.
比較例１〜４の光触媒粉末のそれぞれについて、以下のように光触媒活性を評価した。
脱イオン水を２５０ｍＬを含む内容積３５０ｍＬの透明ガラス（パイレックス（登録商標）製反応容器に、実施例１で合成したＴａＯＮ粉末、または比較例（１）〜（４）で調製した比較用ＴａＯＮ光触媒粉末、のいずれかを５０ｍｇ加え、マグネチックスターラーを用いて約１０００ｒｐｍで撹拌して懸濁させた。この懸濁液にさらにｐＨ調整剤として酸化ランタン（Ｌａ2Ｏ3、和光純薬工業株式会社、９９．５％）を０．２ｇ、および電子受容体として硝酸銀（ＡｇＮＯ3、和光純薬工業株式会社、９９．８％）を０．５４ｇ（３．２ｍｍｏｌに相当）加えた。反応容器を閉鎖循環ラインに接続し、この系内をアルゴンガスで置換した。反応容器を１５℃に設定した恒温槽内の純水中に沈めた。光源として、カットオフフィルター（ＨＯＹＡ製、Ｌ−４２）を装着した３００Ｗキセノンランプ（Ｃｅｒｍａｘ社製）を用い、波長４００ｎｍ以上の可視光を照射させた。反応容器内の水性懸濁液に照射して、ＴａＯＮ半導体粒子内に生成した励起電子によって銀イオン（Ａｇ+）を還元させるとともに、正孔によって水を酸化させて酸素を発生させた。光照射によって発生した酸素の量をガスクロマトグラフ（島津製、カラム：ＭＳ−５Ａ）を使用して追跡することにより、水の光触媒的酸化反応を追跡した。キャリアガスとしてアルゴンを使用し、流量を４０ｍＬ／ｍｉｎとした。
光照射時間に対して発生した酸素ガスの量（μｍｏｌ）をプロットした（図１および図２）。
About each of the photocatalyst powder of Comparative Examples 1-4, photocatalytic activity was evaluated as follows.
Transparent glass containing 250 mL of deionized water (TaON powder synthesized in Example 1 in a Pyrex (registered trademark) reaction vessel, or a comparative TaON photocatalyst prepared in Comparative Examples (1) to (4)) 50 mg of any one of the powders was added and suspended by stirring at about 1000 rpm using a magnetic stirrer, and lanthanum oxide (La 2 O 3 , Wako Pure Chemical Industries, Ltd.) was further added as a pH adjuster to this suspension. , 99.5%) 0.2 g, and 0.54 g (corresponding to 3.2 mmol) of silver nitrate (AgNO 3 , Wako Pure Chemical Industries, 99.8%) as an electron acceptor was added. This system was connected to a closed circulation line, and the inside of the system was replaced with argon gas, and the reaction vessel was submerged in pure water in a thermostatic bath set at 15 ° C. As a light source, a cut-off filter (H Using a 300 W xenon lamp (manufactured by Cermax, Inc., equipped with YA, L-42), visible light having a wavelength of 400 nm or more was irradiated to irradiate the aqueous suspension in the reaction vessel into the TaON semiconductor particles. Silver ions (Ag + ) were reduced by the generated excited electrons, and water was oxidized by holes to generate oxygen.The amount of oxygen generated by light irradiation was measured using a gas chromatograph (manufactured by Shimadzu, column: MS-5A). The photocatalytic oxidation reaction of water was followed using argon as the carrier gas and the flow rate was 40 mL / min.
The amount of oxygen gas (μmol) generated against the light irradiation time was plotted (FIGS. 1 and 2).
図１、２に見られるように、Ｃｏ2+種を用いない場合には、酸素生成速度が反応開始１時間程度で急速に低下し、２時間以降は極めて低い活性となる（ＴａＯＮ無担持）。これは、光照射によってＴａＯＮ半導体粒子内に生成した正孔がＴａＯＮ自身を酸化して、その光触媒活性を低下させるためである。これに対して、Ｃｏ2+種を用いると、酸素生成は大きく向上し、特にＣｏＣｌ2前駆体を用いた場合（図１）において確認されるように、活性が顕著に低下することなく継続し、最終酸素生成量は水溶液中に含まれる３．２ｍｍｏｌの銀イオン（Ａｇ+）が銀（Ａｇ）へと全て還元された場合に想定される理論生成量（０．８ｍｍｏｌ、水の酸化による酸素生成が４電子過程であるため）にほぼ到達した。これは、Ｃｏ2+種が正孔による水の酸化反応（酸素生成）を促進することにより、正孔によるＴａＯＮの自己酸化失活が効果的に抑制されたためである。図１のグラフから、本発明に従う方法によって、含浸担持法により調製された光触媒を使用する場合にほぼ匹敵する高い収率で、水を光触媒的に酸化できることがわかる。本発明によれば、従来の方法と比べて簡便な操作および装置で実施できるにもかかわらず、低コストで水を分解して水素および酸素を高収率で製造できる。 As can be seen in FIGS. 1 and 2, when no Co 2+ species is used, the oxygen production rate decreases rapidly after about 1 hour from the start of the reaction, and becomes extremely low after 2 hours (no TaON supported). . This is because holes generated in the TaON semiconductor particles by light irradiation oxidize TaON itself and reduce its photocatalytic activity. In contrast, the use of Co 2+ species greatly improved oxygen generation and continued without significant decrease in activity, especially as confirmed by the use of a CoCl 2 precursor (FIG. 1). The final oxygen production amount is the theoretical production amount (0.8 mmol, oxygen due to oxidation of water) when 3.2 mmol silver ions (Ag + ) contained in the aqueous solution are all reduced to silver (Ag). The production is almost 4). This is because the Co 2+ species promotes the oxidation reaction (oxygen generation) of water by holes, thereby effectively suppressing the self-oxidation deactivation of TaON by holes. From the graph of FIG. 1, it can be seen that the process according to the present invention allows photocatalytic oxidation of water with a high yield that is almost comparable to the use of a photocatalyst prepared by an impregnation support process. According to the present invention, hydrogen and oxygen can be produced in a high yield by decomposing water at a low cost, although it can be carried out with simple operations and apparatuses as compared with conventional methods.
比較例５〜７：電極の作成
（１）タングステン酸ナトリウム二水和物（和光純薬工業株式会社、９９．０％）８．２５ｇ（２５ｍｍｏｌ）を脱イオン水３０ｍＬに溶解させ、この水溶液を陽イオン交換樹脂（ＤＯＷＥＸ５００Ｗ−Ｘ２）約５０ｇに通すことによって、ナトリウムイオンをプロトンに交換し、この溶液を１００ｍＬのエタノールに滴下し、さらにポリエチレングリーコール３００（和光純薬工業株式会社）３０ｇを加えて、マグネチックスターラーで撹拌し、均一な溶液を得た。この溶液をローターリーエバポレーターによって、約２５ｍＬまで濃縮し、タングステン酸コロイド溶液を調製した。透明導電性フッ素ドープ酸化スズガラス（ＦＴＯ、旭硝子）を幅１５ｍｍ、長さ５０ｍｍに切り出し、アセトン、およびイソプロピルアルコール中において超音波洗浄し、乾燥させた。このＦＴＯ基板の上下５ｍｍを透明テープ（スコッチテープ）によってマスキングした後に、ガラス棒を用いて先のタングステン酸コロイド溶液を塗り伸ばして塗布した。乾燥後、卓上マッフル炉（株式会社デンケン、ＫＤＦ−Ｓ７０）中において、空気雰囲気下、５００℃で１時間加熱焼成を行った。この、塗布・焼成の一連の作業を４回繰り返すことによって、多孔質ＷＯ3電極（比較例５）（無担持）を作成した。幅１５ｍｍ、長さ４０ｍｍに塗布されているＷＯ3の重量は、おおよそ７ｍｇであった。
（２）比較例５と同様に作成した多孔質ＷＯ3電極を、卓上マッフル炉（株式会社デンケン、ＫＤＦ−Ｓ７０）中において、空気雰囲気下、１００℃で１時間加熱焼成を行うことにより、Ｃｏ2+種を担持させた多孔質ＷＯ3電極（比較例６）（浸漬後焼成１００℃）を作成した。
（３）焼成温度を２００℃に変えた以外は、比較例６と同様の手法により、Ｃｏ2+種を担持させた多孔質ＷＯ3電極（比較例７）（浸漬後焼成２００℃）を作成した。
（４）焼成温度を３００℃に変えた以外は、比較例６と同様の手法により、Ｃｏ2+種を担持させた多孔質ＷＯ3電極（比較例８）（浸漬後焼成３００℃）を作成した。
Comparative Examples 5 to 7: Preparation of electrodes (1) 8.25 g (25 mmol) of sodium tungstate dihydrate (Wako Pure Chemical Industries, Ltd., 99.0%) was dissolved in 30 mL of deionized water. By passing about 50 g of cation exchange resin (DOWEX500W-X2), sodium ions are exchanged for protons, this solution is dropped into 100 mL of ethanol, and 30 g of polyethylene glycol 300 (Wako Pure Chemical Industries, Ltd.) is added. The mixture was stirred with a magnetic stirrer to obtain a uniform solution. This solution was concentrated to about 25 mL with a rotary evaporator to prepare a tungstic acid colloid solution. Transparent conductive fluorine-doped tin oxide glass (FTO, Asahi Glass) was cut into a width of 15 mm and a length of 50 mm, ultrasonically washed in acetone and isopropyl alcohol, and dried. After masking 5 mm above and below the FTO substrate with a transparent tape (scotch tape), the above-mentioned tungstic acid colloid solution was spread and applied using a glass rod. After drying, baking was performed at 500 ° C. for 1 hour in an air atmosphere in a desktop muffle furnace (Denken Co., Ltd., KDF-S70). By repeating this series of coating and firing operations four times, a porous WO 3 electrode (Comparative Example 5) (unsupported) was prepared. The weight of WO 3 applied to a width of 15 mm and a length of 40 mm was approximately 7 mg.
(2) A porous WO 3 electrode prepared in the same manner as in Comparative Example 5 was heated and fired at 100 ° C. for 1 hour in a table-top muffle furnace (Denken Co., Ltd., KDF-S70) in an air atmosphere. A porous WO 3 electrode (Comparative Example 6) supporting 2+ species (baked after immersion at 100 ° C.) was prepared.
(3) A porous WO 3 electrode (Comparative Example 7) carrying Co 2+ species (Comparative Example 7 after baking) was prepared in the same manner as Comparative Example 6 except that the firing temperature was changed to 200 ° C. did.
(4) A porous WO 3 electrode (Comparative Example 8) carrying Co 2+ species (Comparative Example 8) (fired after immersion at 300 ° C.) was prepared in the same manner as in Comparative Example 6 except that the firing temperature was changed to 300 ° C. did.
実施例３：電極の作成
比較例５と同様に作成した多孔質ＷＯ3電極に、Ｃｏとして０．５ｗｔ％になるように、ｍＭのＣｏＣｌ2水溶液を滴下させ、空気中において室温で乾燥させることにより、Ｃｏ2+種を担持させた多孔質ＷＯ3電極（実施例３）（滴下）を作成した。
実施例４：電極の作成
比較例５と同様に作成した多孔質ＷＯ3電極を５０ｍＭのＣｏＣｌ2水溶液（２０ｍＬ）中に１時間浸漬させた後に取り出し、脱イオン水を用いてよく洗浄を行った。これを空気中において室温にて乾燥させることにより、Ｃｏ2+種を担持させた多孔質ＷＯ3電極（実施例４）（浸漬）を作成した。
Example 3 Preparation of Electrode To a porous WO 3 electrode prepared in the same manner as in Comparative Example 5, an aqueous solution of mM CoCl 2 was dropped so as to be 0.5 wt% as Co, and dried in air at room temperature. Thus, a porous WO 3 electrode (Example 3) (dropping) carrying Co 2+ species was prepared.
Example 4 Preparation of Electrode A porous WO 3 electrode prepared in the same manner as in Comparative Example 5 was immersed in a 50 mM CoCl 2 aqueous solution (20 mL) for 1 hour and then taken out and washed thoroughly using deionized water. . This was dried in air at room temperature to prepare a porous WO 3 electrode (Example 4) (immersion) supporting Co 2+ species.
電極の評価
上記のように作製した比較例５〜７及び実施例３及び４の電極のそれぞれを光電極（作用電極）として使用し、以下のようにして、光照射により発生した電流の経時変化を測定した。
電解質溶液として０．１ＭのＮａ2ＳＯ4水溶液を使用した。参照電極としてＡｇ／ＡｇＣｌを使用し、作用電極の電位を参照電極に対して＋０．６Ｖにした。作用電極に光を照射するための光源として３００Ｗキセノンランプ（波長＞３００ｎｍ）を使用した。測定電流の経時変化をプロットした（図３）。
Evaluation of Electrode Each of the electrodes of Comparative Examples 5 to 7 and Examples 3 and 4 prepared as described above was used as a photoelectrode (working electrode), and changes with time of current generated by light irradiation were as follows. Was measured.
A 0.1 M aqueous Na 2 SO 4 solution was used as the electrolyte solution. Ag / AgCl was used as a reference electrode, and the potential of the working electrode was +0.6 V with respect to the reference electrode. A 300 W xenon lamp (wavelength> 300 nm) was used as a light source for irradiating the working electrode with light. The change over time of the measured current was plotted (FIG. 3).
作用電極の電位を参照電極に対して＋０．８Ｖにしたことを除いて上記と同様にして、比較例５〜７及び実施例３及び４の電極のそれぞれについて、光照射により発生した電流の経時変化を測定した。測定電流の経時変化をプロットした（図４）。 In the same manner as described above except that the potential of the working electrode was set to +0.8 V with respect to the reference electrode, the time of current generated by light irradiation for each of the electrodes of Comparative Examples 5 to 7 and Examples 3 and 4 was changed. Changes were measured. The change over time of the measured current was plotted (FIG. 4).
Claims (12)
光触媒及びＣｏ2+イオンを含む水を用意する工程、及び
前記光触媒に光を照射して水を水素及び酸素に分解する工程、
を含むことを特徴とする方法。 A method for producing hydrogen and oxygen by decomposing water with a photocatalyst,
A step of preparing water containing photocatalyst and Co 2+ ions, and a step of irradiating the photocatalyst with light to decompose water into hydrogen and oxygen,
A method comprising the steps of:
前記光触媒による水の分解反応により生成した酸素ガス及び水素ガスを回収するためのガス回収装置と、
を含む、水素及び酸素の製造装置。 A reactor for introducing water containing photocatalyst and Co 2+ ions to decompose water by the photocatalyst;
A gas recovery device for recovering oxygen gas and hydrogen gas generated by water decomposition reaction by the photocatalyst;
An apparatus for producing hydrogen and oxygen.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012019356A JP2013154333A (en) | 2012-01-31 | 2012-01-31 | Method and apparatus for producing hydrogen and oxygen by decomposing water with photocatalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2012019356A JP2013154333A (en) | 2012-01-31 | 2012-01-31 | Method and apparatus for producing hydrogen and oxygen by decomposing water with photocatalyst |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2013154333A true JP2013154333A (en) | 2013-08-15 |
Family
ID=49050064
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2012019356A Pending JP2013154333A (en) | 2012-01-31 | 2012-01-31 | Method and apparatus for producing hydrogen and oxygen by decomposing water with photocatalyst |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2013154333A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015116535A (en) * | 2013-12-18 | 2015-06-25 | トヨタ自動車株式会社 | Catalyst for water-splitting reaction |
| CN105854905A (en) * | 2016-05-06 | 2016-08-17 | 江苏大学 | Silver iodide/tungsten oxide composite nanomaterial and preparation method and application thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57500644A (en) * | 1980-04-04 | 1982-04-15 | ||
| JP2000503595A (en) * | 1996-10-07 | 2000-03-28 | コリア リサーチ インスティテュート オブ ケミカル テクノロジー | Novel ZnS photocatalyst, method for producing the same, and method for producing hydrogen using the same |
| WO2010149682A1 (en) * | 2009-06-24 | 2010-12-29 | Basf Se | Method for photocatalytic water purification |
-
2012
- 2012-01-31 JP JP2012019356A patent/JP2013154333A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57500644A (en) * | 1980-04-04 | 1982-04-15 | ||
| JP2000503595A (en) * | 1996-10-07 | 2000-03-28 | コリア リサーチ インスティテュート オブ ケミカル テクノロジー | Novel ZnS photocatalyst, method for producing the same, and method for producing hydrogen using the same |
| WO2010149682A1 (en) * | 2009-06-24 | 2010-12-29 | Basf Se | Method for photocatalytic water purification |
Non-Patent Citations (4)
| Title |
|---|
| JPN6015017059; 佐山和弘: '太陽光水素製造-理想の人工光合成を目指して' 応用物理学関係連合講演会講演予稿集（ＣＤ-ＲＯＭ） ５８ｔｈ, 20110309, ２４Ｐ-ＢＶ-６ * |
| JPN6015017060; 荒野大輔ら: 'ＷＯ３光触媒を用いた光触媒-電解ハイブリッドによる水素製造' 触媒討論会討論会Ａ予稿集 １０４ｔｈ, 20090927, ３４６ * |
| JPN6015017062; Ｍ．Ａ． ＧＯＮＤＡＬ ｅｔ ａｌ．: 'Ｌａｓｅｒ Ｉｎｄｕｃｅｄ Ｐｈｏｔｏｃａｔａｌｙｔｉｃ Ｓｐｌｉｔｔｉｎｇ ｏｆ Ｗａｔｅｒ Ｏｖｅｒ ＷＯ３ Ｃａｔａｌｙｓｔ' Ｅｎｅｒｇｙ Ｓｏｕｒｃｅｓ Ｖｏｌｕｍｅ ２７， Ｉｓｓｕｅ １２, 20060820, ｐａｇｅｓ １１５１-１１６５ * |
| JPN6015017063; Ｍ． ＡＳＨＯＫＫＵＭＡＲ: 'Ａｎ ｏｖｅｒｖｉｅｗ ｏｎ ｓｅｍｉｃｏｎｄｕｃｔｏｒ ｐａｒｔｉｃｕｌａｔｅ ｓｙｓｔｅｍｓ ｆｏｒ ｐｈｏｔｏｐｒｏｄｕｃｔｉｏｎ ｏｆ ｈｙｄｒｏｇｅｎ' Ｉｎｔｅｒｎａｔｉｏｎａｌ Ｊｏｕｒｎａｌ ｏｆ Ｈｙｄｒｏｇｅｎ Ｅｎｅｒｇｙ Ｖｏｌｕｍｅ ２３， Ｉｓｓｕｅ ６, 19980619, Ｐａｇｅｓ ４２７-４３８ * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2015116535A (en) * | 2013-12-18 | 2015-06-25 | トヨタ自動車株式会社 | Catalyst for water-splitting reaction |
| CN105854905A (en) * | 2016-05-06 | 2016-08-17 | 江苏大学 | Silver iodide/tungsten oxide composite nanomaterial and preparation method and application thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wen et al. | Plasmonic Au@ Pd nanoparticles supported on a basic metal–organic framework: Synergic boosting of H2 production from formic acid | |
| Tian et al. | Fabrication of an efficient noble metal-free TiO2-based photocatalytic system using Cu–Ni bimetallic deposit as an active center of H2 evolution from water | |
| An et al. | Plasmonic silver incorporated silver halides for efficient photocatalysis | |
| Sun et al. | Fe and Ni co-doped TiO2 nanoparticles prepared by alcohol-thermal method: Application in hydrogen evolution by water splitting under visible light irradiation | |
| He et al. | Photocatalytic reduction of CO2 in aqueous solution on surface-fluorinated anatase TiO2 nanosheets with exposed {001} facets | |
| Erbs et al. | Visible-light-induced oxygen generation from aqueous dispersions of tungsten (VI) oxide | |
| JP4564263B2 (en) | Ultrafine metal particle-containing photocatalyst and method for producing the same | |
| EP3427826B1 (en) | Catalyst and use of same | |
| Najafabadi et al. | Cobalt precursor role in the photocatalytic activity of the zeolite-supported TiO2-based photocatalysts under visible light: A promising tool toward zeolite-based core–shell photocatalysis | |
| CN110983362B (en) | MOFs-coated OV-BiVO4Composite photo-anode and preparation method and application thereof | |
| JP5999548B2 (en) | Photocatalyst and method for producing the same | |
| Naaz et al. | Unraveling the chemoselective catalytic, photocatalytic and electrocatalytic applications of copper supported WO3 nanosheets | |
| JP2015116535A (en) | Catalyst for water-splitting reaction | |
| Zheng et al. | Hollow titania spheres loaded with noble metal nanoparticles for photocatalytic water oxidation | |
| Wang et al. | Effects of NH4F quantity on N-doping level, photodegradation and photocatalytic H2 production activities of N-doped TiO2 nanotube array films | |
| JP3455779B2 (en) | Apparatus for producing hydrogen comprising semiconductor photocatalyst reactor and electrolyzer | |
| JP4997454B2 (en) | Semiconductor electrode and energy conversion system using the same | |
| JP2013154333A (en) | Method and apparatus for producing hydrogen and oxygen by decomposing water with photocatalyst | |
| Cordeiro et al. | Water oxidation reaction catalyzed by Co3O4 treated with organic compounds | |
| JP5675224B2 (en) | Visible light water splitting catalyst and photoelectrode manufacturing method | |
| JP3793800B2 (en) | Method for producing hydrogen and oxygen using iodine compound and semiconductor photocatalyst | |
| Stroyuk et al. | Gelatin-templated mesoporous titania for photocatalytic air treatment and application in metal chalcogenide nanoparticle-sensitized solar cells | |
| JP2005068007A (en) | Method for manufacturing hydrogen and oxygen by iodine compound and semiconductor photocatalyst | |
| JP6521316B2 (en) | Semiconductor photocatalyst having characteristic absorption band and method of manufacturing the same | |
| US20170312744A1 (en) | Metal deposition using potassium iodide for photocatalysts preparation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20140307 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20141211 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20141216 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20150122 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20150428 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20150717 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20150831 |
|
| A912 | Re-examination (zenchi) completed and case transferred to appeal board |
Free format text: JAPANESE INTERMEDIATE CODE: A912 Effective date: 20150918 |