Sulfate radical dominated rapid pollutants degradation leaded by selenium vacancies in core-shell N-doped carbon wrapped cobalt diselenide nanospheres.

Herein, a new heterogeneous CoSe@NC material with abundant selenium vacancies is synthesized via an in-situ carbonization-selenization process from cobaltic metal organic framework (Co-MOF). The obtained CoSe@NC has a unique electronic structure and rich active sites, which can activate peroxymonosulfate (PMS) to degrade carbamazepine (CBZ) with superior catalytic performance and stability. The quenchingexperiments and EPR test show that SO is the dominant reactive oxidation species (ROSs) for CBZ degradation. Significantly, systemic electrochemical tests and theoretical calculations illustrated that the dominant role of SO is attributed to the existence of abundant selenium vacancies in CoSe@NC, which can adjust the density of electron cloud of the Co atoms in CoSe@NC to improve the PMS adsorption and promoting the conversion of transition metallic redox pairs (Co/Co). This work provides a facile way to improve the activity and stability of CoSe by defect engineering in the PMS based advanced oxidation process (AOPs).