The Award of The Electrochemical Society of Japan (Takei Award)
Development of Photocatalysts for Artificial Photosynthesis Aiming at Carbon Neutrality
2025 年 93 巻 10 号 p. 101001
詳細
2025 年 93 巻 10 号 p. 101001
A library of hundreds of metal oxide and metal sulfide photocatalysts has been constructed based on our original strategies of photocatalyst design that were metal cation doping, new valence band formation, and making a solid solution. Various single particulate and Z-scheme photocatalyst systems that are active in visible-light water splitting have been developed. By the doping strategy, SrTiO3:Rh,Sb and SrTiO3:Ir,Sb,Al of a single particulate metal oxide photocatalyst were developed for water splitting working under visible light irradiation. BiVO4 was developed for water oxidation to form O2 under visible light irradiation by the new valence band formation with Bi6s orbitals. Several types of a Z-scheme system have been constructed by using SrTiO3:Rh of a H2-evolving photocatalyst, BiVO4 of an O2 evolving photocatalyst, and a suitable electron mediator such as Fe3+/2+, Co(bpy)33+/2+, reduced graphene oxide (RGO), and poly-3,4-ethylenedioxythiophene (PEDOT). A CuGaS2-ZnS solid solution photocatalyst was active for sacrificial H2 evolution, and it was able to be applied to a Z-scheme photocatalyst with BiVO4 of an O2-evolving photocatalyst for water splitting without any sacrificial reagents. Novel cocatalysts such as Ag and Rh-Ru were found for photocatalytic CO2 reduction using water as an electron donor. Ag/NaTaO3:Ba and Rh-Ru/NaTaO3:Sr photocatalysts gave 90 % and 10 % of an electron-based selectivity for the CO2 reduction to form CO and CH4 accompanied with stoichiometric O2 evolution even in an aqueous solution under UV irradiation, respectively. A Z-scheme photocatalyst consisting of CuGaS2-ZnS and BiVO4 was active for the CO2 reduction to form CO with 12 % of the selectivity under visible light irradiation in an aqueous suspension system.
