MoS2/α-FeOOH heterojunction composites with enhanced photo-Fenton performance

As-synthesized MoS2/α-FeOOH heterojunction exhibits efficient reactivities for Fenton and photo-Fenton degradation of acid orange 7 (AO7) and sulfamethoxazole. Work functions investigated by DFT method suggest a spontaneous electron transfer from MoS2 to α-FeOOH by constructing a type II heterojunction. The electron transfer across the heterojunction was further confirmed by XPS observation. The carrier transfer can be maintained and intensified by surface redox reaction of H2O2 with the accumulated carriers, which amplifies the role of heterojunction. The reaction rate constant for photo-Fenton degradation of AO7 with MoS2/α-FeOOH-10 is 6.6 times higher than that of α-FeOOH. Notably, although α-FeOOH cannot absorb the 660 nm irradiation, a much-enhanced photo-Fenton degradation of AO7 with MoS2/α-FeOOH-10 under 660 nm irradiation further verifies the occurrence of electron transfer from MoS2 to α-FeOOH. This work provides an in-depth observation on the role of type II heterojunction in promoting the photo-Fenton reactivity for organic degradation.