Perovskite manganese oxides with tunable metal-oxygen covalency for efficient bisphenol A degradation

Direct oxidation of organic pollutants by manganese oxides is appealing for the removal of persistent organic pollutants (POPs) since it requires no chemical dosing. Rapid electron transfer and moderate adsorption are vital in manganese-induced oxidation. In this study, we used perovskite lanthanum manganate (LaMnO3) as a model to explore the relationship between bisphenol A (BPA) removal efficiency and metal-oxygen covalency, which is closely related to electron transfer and adsorption capacity, by introducing other metals or defects at the A-site. X-ray absorption spectra (XAS) and density functional theory (DFT) calculation showed that the charge migration rate and BPA adsorption capacity on manganese oxides increase with the increase of metal-oxygen covalency. The manganese oxides with medium metal-oxygen covalency have the strongest oxidation capability toward BPA. Our work provides new regulatory strategies for enhancing the oxidation ability of manganese oxides to directly decompose organic pollutants via interfacial electron transfer. The metal-oxygen covalency of manganese oxides is the main factor affecting the degradation efficiency of persistent organic pollutants in water.