Recent advances in molybdenum disulfide-based advanced oxidation processes

Molybdenum disulfide (MoS2) is an emerging class of heterogeneous catalyst in advanced oxidation processes (AOPs). Featuring a two-dimensional structure, good conductivity, photo-response, reductive capacity, and regulatable active sites, MoS2 fulfills versatile functions in various AOPs systems, such as direct activation of peroxide, serving as a co-catalyst in Fe3+- and Cu2+-based Fenton/Fenton-like systems, photocatalytic oxidation, electrochemical oxidation, and piezoelectric oxidation. In this review, we summarize recent advances of MoS2 in the AOPs applications. We systematically compare the dominant reactive oxygen species, and identify potential active sites (e.g., edges and vacancy defects) and the impact of the crystal structure (e.g., 1T phase). We also introduce some basic principles based on the structure-activity relationships to describe the intrinsic activation mechanisms. In addition, we discuss discrepancies in previous reports on MoS2-based AOP systems. Finally, roadblocks are identified and future orientation is directed regarding catalyst design, system optimization, and practical applications.