Spontaneous generation of reactive oxygen species via molecular oxygen activation over a defect-rich and boron-doped MoS₂ catalyst for an advanced oxidation process

Abstract

With the proposal of a low carbon strategy, spontaneous generation of reactive oxygen species (ROS) via O2 activation under mild ambient conditions is considered an environmentally friendly and cost-effective technology for an advanced oxidation process. Herein, a novel O2 activation system based on a defect-rich and boron-doped MoS2 catalyst (B-MoS2–x) was constructed for organics degradation without the addition of oxidants and energy consumption. This system enabled electron transfer from organic pollutants to O2 under the effect of an interfacial microelectric field, exhibiting high catalytic activity and stability. Even after five-cycle use, the decrease in organics degradation efficiency in the B-MoS2–x/air system is less than 5%. The long-term RhB elimination experiment is conducted in a homemade continuous-flow membrane-based reactor, which demonstrated that the B-MoS2–x/air system can be operated continuously and steadily for 48 h. Due to the difference of adsorption energy, O2 and organics were, respectively, adsorbed on S defect and B, further facilitating activation of O2 to ROS for organics degradation. Additionally, the turnover frequency of O2·– production over B-MoS2–x reaches 2.93 h–1, and the biotoxicity of the pollutants is decreased obviously in the B-MoS2–x/air system. This work provided a new idea to promote the research of the microelectric field for O2 activation to ROS.