Reinventing MoS2 Co-catalytic Fenton reaction: Oxygen-incorporation mediating surface superoxide radical generation

To better understand the mechanisms of hydrogen peroxide (H2O2)'s decomposition and reactive oxygen species (ROS)'s formation on the catalyst's surface is always a critical issue for the environmental application of Fenton/Fenton-like reaction. We here report a new approach to activate H2O2 in a co-catalytic Fenton system with oxygen incorporated MoS2, namely MoS2-xOx nanosheets. The MoS2-xOx nanosheets assisted co-catalytic Fenton system exhibited superior degradation activity of emerging antibiotic contaminants (e.g., sulfamethoxazole). Combining density functional theory (DFT) calculation and experimental investigation, we demonstrated that oxygen incorporation could improve the intrinsic conductivity of MoS2-xOx nanosheets and accelerate surface/interfacial charge transfer, which further leads to the efficacious activation of H2O2. Moreover, by tuning the oxygen proportion in MoS2-xOx nanosheets, we are able to modulate the generation of ROS and further direct the oriented-conversion of H2O2 to surface-bounded superoxide radical (center dot O-2 surface(-)). It sheds light on the generation and transformation of ROS in the engineered system (e.g., Fenton, Fenton-like reaction) for efficient degradation of persistent pollutants.