Development of single particulate metal oxide photocatalysts being active for water splitting under visible light irradiation and CO₂ reduction using water as an electron donor

Abstract

It is important to develop the technology of production of green hydrogen for realization of the carbon neutral society. In recent years, the artificial photosynthetic photocatalyst has gained much attention as a promising production method of row-cost green hydrogen. In this topic, we introduce the stage-of-the-art single particulate metal oxide photocatalyst as artificial photosynthesis developed by our group. SrTiO₃ photocatalysts doped with aluminum and small amounts of transition metals such as Cr, Ir, Rh, and Ru show the high activity for water splitting under visible light irradiation. In addition, a Sr-doped NaTaO₃ photocatalyst loaded with a Rh-Ru dual metal cocatalyst evolve methane of an eight-electron reduction product by CO₂ reduction under UV light irradiation using water as an electron donor. Improvement in the quality of the host material and the development of the suitable cocatalyst as an active site are important issues for enhancement of the photocatalytic activity.