Fenton-like catalysis by MnO2 membrane reactor with oxygen vacancies for carbamazepine degradation

Pathway design for singlet oxygen (1O2) with in-situ regulation has shown great interest for peroxymonosulfate (PMS) activation toward advanced oxidation in water treatment. Herein, we propose a facile method to design MnO2 catalysts with tunable surface oxygen vacancies (OVs) concentration to achieve radical-to-nonradical pathway transition. The surface of the OVs-rich NFM-140 provides an optimal site for PMS adsorption and allows •OH to break through the energy demand limitation and preferentially convert to 1O2 for electrophilic attack to pollutants. This OVs-regulated oxidation system can selectively switch to the 1O2-dominated nonradical pathway in response to pollutant recalcitrance, perfectly eliminating the pollutants and transforming them into the harmless products. Our research presents a novel perspective on the selective generation of reactive oxygen species (ROS) for the degradation of organic pollutants in PMS by utilizing the mediation of OVs.