Mechanism and performance evaluation of FeSe2 and MoS2-loaded carbon fiber sheet as a novel heterogeneous Fenton-like catalyst

• FeSe 2 and MoS 2 are combined to activate H 2 O 2 in Fenton reaction is reported for the first time. • The adsorption capacity of MoS 2 in the MoS 2 @FeSe 2 @CFS can confine the pollutant to the catalyst, thus shortening the mass transfer distance. • There are excellent catalytic activity and stability of catalyst in H 2 O 2 / MoS 2 @FeSe 2 @CFS systems for MB wastewater. • The S 2 2- species in MoS 2 participates in Fe 3+ /Fe 2+ cycle, and enhances the synergy between FeSe 2 and MoS 2 . A novel non-woven carbon fiber sheet-supported FeSe 2 and MoS 2 -loaded Fenton catalyst (MoS 2 @FeSe 2 @CFS) was synthesized by a two-step hydrothermal process. The MoS 2 @FeSe 2 @CFS exhibited an excellent performance on hydrogen peroxide (H 2 O 2 ) activation at different conditions. Removal efficiency of methylene blue (MB) reached 99.7% within 20 min and the rate constant was higher than those of the most reported iron-containing catalyst/H 2 O 2 systems for MB degradation. The possible activation mechanism of H 2 O 2 by MoS 2 @FeSe 2 @CFS in heterogeneous system was proposed·H 2 O 2 was activated to ·OH by Fe 2+ , and generated Fe 3+ was reduced to Fe 2+ by Mo 4+ . Besides, MoS 2 has great adsorption performance and can aggregate MB near the catalyst, shortening the mass transfer distance. Therefore, the heterogeneous Fenton catalyst MoS 2 @FeSe 2 @CFS has excellent catalytic property. Notably, it was discovered that S might participate in the Fe 3+ /Fe 2+ cycle, which has not been reported in literature. Moreover, MoS 2 @FeSe 2 @CFS have good long-term stability and repeatability because of its high strength and chemical durability. Overall, this work expands the environmental application of iron-containing catalyst and provides a promising heterogeneous Fenton system for removal of contaminants from water.