Near-infrared light-inducible Z-scheme overall water-splitting photocatalyst without an electron mediator

Abstract

We facilely prepared a solid-state heterojunction photocatalyst in which silver vanadium oxide (Ag₂V₄O₁₁) and zinc rhodium oxide (ZnRh₂O₄) as oxygen and hydrogen evolution photocatalysts, respectively, were directly connected to generate Ag₂V₄O₁₁/ZnRh₂O₄. Ag₂V₄O₁₁/ZnRh₂O₄ photocatalyzed overall pure-water splitting without any electron mediator under irradiation with near-infrared light at wavelengths of up to 910 nm. The key points are that the conduction bottom potential of Ag₂V₄O₁₁ is almost the same as the valence band top potential of ZnRh₂O₄, and that the bandgaps of Ag₂V₄O₁₁ and ZnRh₂O₄ are 1.4 and 1.2 eV, respectively.