In situ interfacial engineering modulated adsorption and electron transfer boosting peroxymonosulfate activation for micro-contaminates degradation over CoOx nanosheet

Cobalt-based oxides have attracted extensive attention in heterogeneous catalytic peroxymonosulfate (PMS) activation towards emerging pollutants degradation, while the improvement of their catalytic performance is still a severe challenge. Herein, a CoO x ultrathin nanosheet composed of in situ interfacial Co 3 O 4 and CoO (CoO x -Ar-350) was synthesized and employed in PMS activation for micro-contaminates removal. The catalyst shows 100 % bisphenol A (BPA) conversion within 2 min ([BPA] = 20 mg/L, [Catalyst] = 20 mg/L, [PMS] = 200 mg/L) with a remarkable reaction rate of 2.69 min −1 , which is 3.84 and 2.66 times of pure Co 3 O 4 and CoO, respectively. Characterization and theoretical calculation results indicates that the interfacial synergy between Co 3 O 4 and CoO could modulate the adsorption behavior and enhance the electron acceptance of PMS, which boosts the breaking of O-O bonds and the generation of reactive oxygen species (ROS) and thereby the pollutant removal efficiency. The ROS quenching and capture experiments demonstrate that the enhanced OH and 1 O 2 play significant contribution during the degradation process. This work provides a novel in situ interfacial engineering for the development of highly efficient catalyst and reveals the activity enhancement mechanism for PMS activation.