Selective loading of platinum cocatalyst onto zinc rhodium oxide in a silver-inserted heterojunction overall water-splitting photocatalyst consisting of zinc rhodium oxide and bismuth vanadium oxide

抄録

Platinum (Pt) was selectively photodeposited onto zinc rhodium oxide (ZnRh₂O₄) to serve as a hydrogen (H₂)-evolution photocatalyst in a silver (Ag)-inserted ZnRh₂O₄ and bismuth vanadium oxide (Bi₄V₂O₁₁) solid-state photocatalyst (ZnRh₂O₄/Ag/Bi₄V₂O₁₁). The amount of deposited Pt was controlled by the photodeposition time to generate Pt-loaded ZnRh₂O₄/Ag/Bi₄V₂O₁₁ (Pt/ZnRh₂O₄/Ag/Bi₄V₂O₁₁) containing up to 0.17 wt % of Pt cocatalyst. The prepared Pt/ZnRh₂O₄/Ag/Bi₄V₂O₁₁ photocatalysts were able to catalyze the overall pure-water splitting reaction under irradiation with red light at a wavelength of 700 nm and enhanced the stoichiometric evolution of H₂ and O₂ from water at Pt amounts exceeding 0.12 wt % of Pt. The apparent quantum efficiency of the water-splitting reaction was highest at 0.17 wt % of Pt. In addition to the loading amount of Pt, the loading of Pt as Pt⁰ (metallic Pt) is crucial for enhancing the water-splitting activity of Pt/ZnRh₂O₄/Ag/Bi₄V₂O₁₁.