Theoretical investigation on defect engineering for tuning photocatalytic activities in isostructural ScxmCuynOz−1 (m = Ca, n = Ni)

Abstract

A novel bifunctional photocatalyst for overall water splitting and catalyst separations was realized through defect engineering approach. For the first time a systematic investigation of the photocatalytic activity in isostructural oxide is presented. The analysis are based on the optical absorption, band edge potential, energy band gap, and electrons-holes effective masses. The hole-doped Sc2Cu2O5 compound with Ca@Sc site @25%, show high optical absorption in the visible range and small effective masses efficient to suppress backward oxidation reaction. The computed band edge potentials for both valence and conduction band of the Ni@Cu site are deep enough for these compounds to be use as cocatalyst for either of redox reactions. High absorption under visible light irradiation, and increased spin moment was observed in oxygen vacancy configurations at the Cu coordinated defect sites, which is also characterized by the nearest bond length contraction in Cu-O sites after geometry relaxation.