The vital role of iron sulfides-based materials in advanced oxidation processes: Catalytic abilities, mechanisms, and prospects

Iron sulfides-based advanced oxidation processes (AOPs) have attracted significant attention owing to their intrinsic ability to drive efficient self-enhanced Fe(II)/Fe(III) cycling. Currently, researchers have investigated the efficacy and mechanisms of iron sulfides-based catalysts (mainly including FeS and FeS₂) in activating various advanced oxidants (hydrogen peroxide, sodium percarbonate, peroxydisulfate, peroxymonosulfate, peracetic acid, and periodate) for efficient pollutant degradation. These investigations have demonstrated the activation mechanisms of oxidants by iron sulfides-based catalysts, elucidating the efficiency and pathways of pollutant degradation, providing valuable insights for researchers. Although some reviews of environmental applications of iron sulfides-based catalysts exist, a comprehensive review that systematically analyzes the application of iron sulfides-based catalysts in various AOPs has not been published yet. This work contributes to addresses this gap by thoroughly examining the fundamental properties of iron sulfides-based catalysts and oxidants, catalytic mechanisms categorized by oxidant type, and the latest advancements in pollutant degradation. Additionally, it highlights current challenges, such as catalyst stability and oxidant selectivity, while proposing potential solutions, including surface modification and hybrid material design. This review will provide guidance for the application of iron sulfide-based catalysts in activating various oxidants (including less common oxidants sodium percarbonate, peracetic acid, and periodate) for pollutant removal.