人工光合成のための光触媒材料の開発

金属阳离子掺杂TiO_2和SrTiO_3对含有牺牲试剂的水溶液中H_2或O_2的析出有可见光响应。可见光响应是由于掺杂剂形成的电子从供体能级过渡到宿主光催化剂的导带。共掺杂可以有效补偿过渡金属阳离子掺杂带来的电荷不平衡，从而改善光催化反应的可见光响应。在过渡金属掺杂光催化剂中，SrTiO_3掺杂Rh （SrTiO_3:Rh）是一种在可见光照射下产生H_2的新型金属氧化物光催化剂。利用平衡带控制的能带工程，还制备了Ag_3VO_4、Ag_<0.5>Pr_<0.5>TiO_3和SnNb_2O_6。利用可见光驱动的H_2和O_2析出光催化剂和Fe^<3+>/Fe^<2+>氧化还原偶对作为电子继电器，构建了Z-scheme光催化体系，实现了在可见光照射下水的全面分解。利用窄带隙半导体制备ZnS固溶体，开发了高效的硫化物光催化剂。

Metal cation doping into TiO_2, and SrTiO_3 gave visible light responses for H_2 or O_2 evolution from aqueous solutions containing of sacrificial reagents. The visible light responses were due to the electronic transition from donor levels formed with dopants to conduction bands of the host photocatalysts. Codoping was effective to compensate charge unbalance brought by doping of transition metal cations, resulting in the improvement of visible light response for photocatalytic reactions. Among the transition metal-doped photocatalysts, SrTiO_3 doped with Rh (SrTiO_3:Rh) was the novel metal oxide photocatalyst that produced H_2 under visible light irradiation. Ag_3VO_4, Ag_<0.5>Pr_<0.5>TiO_3, and SnNb_2O_6 were also developed by band engineering of a balance band control. Overall water splitting under visible light irradiation has been achieved by construction of a Z-scheme photocatalysis system employing visible-light-driven photocatalysts for H_2 and O_2 evolution, and an Fe^<3+>/Fe^<2+> redox couple as an electron relay. Moreover, highly efficient sulfide photocatalysts for production of solar hydrogen was developed by making solid solutions of ZnS with narrow band gap semiconductors.