[8p-Z28-1~9] Development of the engineering for the diverse stable phases ~Objectives for the future environment, energy materials and devices

[8p-Z28-8] Solar Hydrogen Production and Materials Development

〇Hiroshi Irie¹ (1.Clean Energy Res. Ctr, Univ. Yamanashi)

Keywords:photocatalysis, hydrogen production, red light

Various photocatalytic materials aiming at water splitting have been enthusiastically investigated because produced hydrogen (H₂) is attractive as a clean and renewable fuel. For the practical application, splitting pure water with no added chemicals is presumed to be favorable.Recently, we reported an Ag-inserted solid-state hetero-junction photocatalyst for water-splitting under visible light, similar to a Z-scheme system but is not required for a redox mediator. So, this system is capable of splitting pure water. In this system, Ag acts as a solid electron mediator for water-splitting. We selected ZnRh₂O₄ (band-gap (Eg) = 1.2 eV) and Bi₄V₂O₁₁ (Eg = 1.7 eV) as H₂- and oxygen (O₂)-evolution photocatalysts, respectively. The prepared system (ZnRh₂O₄/Ag/Bi₄V₂O₁₁) was able to respond to visible light up to 740 nm depending on the photo-absorption capability of Bi₄V₂O₁₁. In addition, after selective loading of a cocatalyst, Ag or Pt, onto ZnRh₂O₄ in ZnRh₂O₄/Ag/Bi₄V₂O₁₁, the overall water-splitting activity enhanced.