In-situ surface chlorination strategy enables highly efficient metal-support catalyst toward chlorophenols pollutants degradation

Abstract

Heterogeneous advanced oxidation processes (AOPs) by metal-support catalysts have been developed to water or wastewater treatment, however several critical issues hampered their real application, including aggregation and loss of catalysts, and the low mass transfer efficiency of radicals. To address these, the surface sonochemical chlorination strategy is proposed to defy the activity-stability trade-off of metal-support catalyst, taking the ZnO supported nanosilver (AgNPs) catalyst (Ag/ZnO) as model, which is controllably evolved into AgCl/Ag/ZnO heterostructure. Their sonocatalysis degradation performance and activity-stability on chlorophenols (CPs) micropollutants are demonstrated. The results show that the cleavage of organic carbon-chlorine (C-Cl) bonds leads to the in-situ generation of AgCl layer on AgNPs, and the produced AgCl/Ag/ZnO heterostructure exhibits a sustained and enhanced sonocatalytic activity for CPs removal. Specifically, AgCl/Ag/ZnO heterostructure really resists to the Ag+ release from AgNPs, and showing advantage for synergistic reduction–oxidation degradation of CPs. This work demonstrates that the in-situ surface chlorination strategy is promising to solve the activity-stability riddle of metal-support catalysts for environmental remediation.