Tuning the photocatalytic activity of layered perovskite niobates by controlled ion exchange and hydration

Abstract

Dion–Jacobson type layered perovskite niobium oxides KCa₂Nb₃O₁₀ and KSr₂Nb₃O₁₀ were prepared via molten salt method, and the potassium cations were exchanged by protons using nitric acid. Different degrees of proton exchange were adjusted, and the dependence of photocatalytic activity for hydrogen evolution on proton exchange was investigated. Moreover, proton exchange leads to different amounts of water incorporated into the interlayer spaces, also influencing photocatalytic performance significantly. Decoupling water intercalation and proton exchange, the photocatalytic activity of proton exchanged KCa₂Nb₃O₁₀ and KSr₂Nb₃O₁₀ can be revealed and tailored.