Interaction mechanism between multi-layered MoS2 and H2O2 for self-generation of reactive oxygen species

Elucidating the generation mechanism of reactive oxygen species (ROS) is essential for advanced oxidation processes with respect to environmental and biological sciences. Herein, self-generation of ROS such as hydroxyl radicals (center dot OH), superoxide radicals (O-2(center dot-)) and singlet oxygen (O-1(2)) from the interaction between multi-layered flowerlike MoS2 nanosheets and H2O2 is presented. The results demonstrate that H2O2 can exfoliate multilayered MoS2 into quantum dots and promote a 2H to 1 T phase change accompanied by the dissolution of MoS2 to produce H+, MoO42+ and SO42-. Electron spin resonance (ESR) spectroscopy confirm the production of center dot OH, superoxide radicals O-2(center dot-) and O-1(2) in the MoS2/H2O2 system. The calculation data based on density functional theory (DFT) indicate that the 1 T-MoS2 can lower the free energy profiles for stepwise catalytic decomposition of H2O2 to produce ROS as compared to 2H-MoS2.