Photocatalytic water oxidation by a pyrochlore oxide upon irradiation with visible light: Rhodium substitution into yttrium titanate

Abstract

A stable visible-light-driven photocatalyst (λ ≥ 450 nm) for water oxidation is reported. Rhodium substitution into the pyrochlore Y2Ti2O7 is demonstrated by monitoring Vegard's law evolution of the unit-cell parameters with changing rhodium content, to a maximum content of 3% dopant. Substitution renders the solid solutions visible-light active. The overall rate of oxygen evolution is comparable to WO3 but with superior light-harvesting and surface-areanormalized turnover rates, making Y2Ti1.94Rh0.06O7 an excellent candidate for use in a Z-scheme water-splitting system.