Multifunctional roles of MoS2 in persulfate-based advanced oxidation processes for eliminating aqueous organic pollutants: A review

Molybdenum disulfide (MoS2) has emerged as a versatile activator in persulfate-based advanced oxidation processes (PS-AOPs). As a polymorphic layered material, MoS2 shows variable physicochemical properties including electrical, optical, catalytic and piezoelectric properties depending on the crystal structure. Accordingly, MoS2 can serve as a cocatalyst/catalyst to directly activate persulfate and the activation efficiency can be further improved through converting external stimulus (e.g., light and mechanical force) into chemical/thermal energy. This review presents the recent advances of MoS2-based materials as effective catalysts in various PS-AOPs. We systematically compare the properties of three MoS2 polytypes (1 T, 2 H and 3 R) and their applications in PS-AOPs. Meanwhile, modifications on MoS2 and the persulfate activation processes with different functions of MoS2-based materials are discussed. Moreover, critical issues and research directions in MoS2 future applications in PS-AOPs are addressed, with prospects towards implementation of self-powered water treatment systems with additional energy recovery.