Synergetic degradation of Methylene Blue through photocatalysis and Fenton reaction on two-dimensional molybdenite-Fe.

The greatest problem in conventional Fenton reaction is the slow production of ROS (reactive oxygen species) because of the inefficient Fe/Fe conversion. Based on the extraordinary photo-response property of two-dimensional molybdenite (2DM), photogenerated electrons can be easy separated to accelerate the regeneration of Fe. In this work, Fe-anchored 2DM (2DM-Fe) was prepared and used as a heterogeneous Fenton catalyst to investigate the degradation efficiency to Methylene Blue (MB) in the presence of light. According to experimental results, 2DM-Fe exhibited extraordinary catalytic activity in MB elimination, which ascribed to the synergetic effect of photogenerated carriers and anchored Fe to HO activation. In addition, 2DM-Fe showed nearly 100% degradation efficiency to MB within 5 cycles with slight leaching amount of Mo and Fe ions, implying the strong stability and reusability in HO system. Furthermore, the influences of HO and 2DM-Fe dosages, pH values as well as the degradation efficiency to different dyes were also investigated. According to quenching experiments and EPR (electron paramagnetic resonance) test, the degradation mechanism of MB mainly ascribed to the oxidation of HO• and •O. This finding provides a novel strategy to design rational Fenton catalyst and has great significance to water remediation in the future.