Highly active heterogeneous FeCo metallic oxides for peroxymonosulfate activation: The mechanism of oxygen vacancy enhancement

Oxygen vacancies (Ov) can improve the electronic structure of catalyst, thus enhancing catalyst activity and reducing metal leaching. In this work, an Ov-enriched FeCo bimetallic catalyst (3DOM FeCo) was designed and prepared. The presence of abundant Ov was observed by Raman measurements and electron paramagnetic resonance (EPR). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) indicated the improvement of electrochemical and photochemical properties of 3DOM FeCo by Ov. The function of Ov as the main active site for PMS adsorption and activation were proved by XPS analysis and density functional theory (DFT). With the superior properties modified by Ov, 3DOM FeCo achieved 100% APAP degradation and 50% mineralization within 60 min. And 3DOM FeCo/PMS system was effective and adaptable in different pH values and real water samples. This work made great efforts in continuously improving catalytic efficiency and solving secondary pollution problems.