Photocatalytic Decomposition of Water on Spontaneously Hydrated Layered Perovskites.

A series of ion-exchangeable layered perovskite type oxides, A2-xLa2Ti3-xNbxO10 (A = K, Rb, Cs; x = 0, 0.5, 1.0), were found to be highly efficient photocatalysts for overall water splitting when a small amount of Ni was loaded. These compounds are spontaneously hydrated even in an aqueous alkaline solution and decompose intercalated H2O molecules into H2 and O2 under the bandgap irradiation.