With the rapid development of persulfate advanced oxidation methods,the improvement of catalysts for the efficient activation of persulfate has attracted considerable attention from researchers worldwide. Among the heterogeneous catalysts for persulfate,metal-based nanomaterials are characterized by good catalytic properties,chemical stability,and reusability,owing to their small particle size,large specific surface area,high specific surface activation energy,and excellent magnetic properties. Therefore,metal-based nanomaterials are considered to be the most suitable materials as persulfate activators and have considerable potential for application in the field of environmental pollution control. However,single metal nanoparticles are prone to particle agglomeration,self-oxidation,and metal ion release during the reaction process,thereby partly limiting the extensive application of metal nanocatalysts. To address this problem,researchers have used composite materials as alternatives to single materials as persulfate activators to treat environmental pollutants. For example,metal nanoparticles have been loaded onto different carrier materials during catalyst preparation,which facilitates synergistic treatment effects,reduces the loss of metal ions,and enhances the reusability of catalysts. In addition,polymetallic nanocomposites with unique structures have been prepared as heterogeneous catalysts,and the synergistic effects of multiple metals have been demonstrated to further enhance the activation performance of catalysts,thereby improving the efficiency of pollutant removal. Numerous studies have recently examined the preparation and structural properties of metal-based nanoparticles,mechanisms underlying the generation of free radical and non-free radical species in activation process of persulfate,and the removal effects and mechanisms of pollutant by metal-based nanocomposites activated persulfate,thereby contributing to valuable research data. In this paper,we present a comprehensive review of the theoretical and applied research that has been conducted on persulfate oxidation using nano-zero-valent metals,nano-metal oxides,nano-ferrite,and supported metal nanoparticles as catalysts. We present a systematic summary of the preparation methods and structural characteristics of different metal nanoparticles,the reaction mechanisms underlying the persulfate activation in generating active species. We also propose that metal nanoparticles have low catalytic stability and certain environmental risks when used for persulfate activation. Moreover,we suggest future research directions,which will serve as a reference for the development and application of safe and efficient metal nanocatalysts for use in the persulfate advanced oxidation. © 2023 Cailiao Daobaoshe/ Materials Review. All rights reserved.
