Oxygen vacancy mediated surface charge redistribution of Cu-substituted LaFeO3 for degradation of bisphenol A by efficient decomposition of H2O2

Abstract

The novel catalyst LaCu0.5Fe0.5O3-δ with oxygen vacancies (OVs) was prepared and demonstrated excellent stability and activity for the degradation of bisphenol A. The removal rate of 92.1 % and H2O2 utilization efficiency of 70.4 % were obtained due to the efficient hydroxyl radical generation mediated by OVs. The density functional theory calculation showed that the substitution of Cu and formation of OVs significantly increases the charge density near the active sites. Bader charge analysis revealed that the charge offset accelerated the reduction of Fe. The elevation of electron transfer efficiency also promotes the valence transition of copper and iron atoms. The reversible electronic transition between Fe2+ ⇆ Fe3+, Cu+ ⇆ Cu2+ and Cu2+ ⇆ Fe2+ involved in this reaction were considered to be enhanced and the homolytic bond clearage of H2O2 was simultaneously promoted, facilitated by the electron-rich region combined with OVs on the surface of LaCu0.5Fe0.5O3-δ.