Enhancing co-catalysis of MoS2 for persulfate activation in Fe3+-based advanced oxidation processes via defect engineering

作者：Kuang, Hainan; He, Zuyun; Li, Mu; Huang, Renfeng; Zhang, Yongqing^*; Xu, Xiaomin; Wang, Lu; Chen, Yan^*; Zhao, Shuaifei

来源：Chemical Engineering Journal, 2021, 417: 127987.

DOI：10.1016/j.cej.2020.127987

• Defect engineering
• Molybdenum disulfide
• Reduction of Fe3+
• Persulfate activation

Advanced oxidation processes (AOPs) based on persulfate (PS) has attracted great attention because of its outstanding performance for decomposing chlorinated aromatic hydrocarbons in wastewater. While Fe-based materials can effectively activate PS and are environment-friendly, the low stability of Fe2+ and little activation capability of Fe3+ limit the broad applications of Fe2+ (or Fe3+) activated PS system in practical applications. In this work, taking molybdenum disulfide (MoS2) as the co-catalyst in Fe3+/PS system, we report a strongly enhanced persulfate activation efficiency of Fe3+/PS system by engineering S defects in MoS2. The combination of experiments and density functional theory (DFT) calculation demonstrate that S defects in MoS2 modify the surface charge distribution, leading to the formation of an electron deficient center near S defect and increasing the electron density near Mo site. As a result, more Fe3+ in Fe3+/PS system is reduced into Fe2+ by MoS2 with S defects, resulting in more reactive oxygen species generated. Furthermore, S defects promote the adsorption of Fe3+ on the MoS2 surface, which further enhance the activating performance for PS through promoting to form cycle of Fe3+/Fe2+. This work provides a new strategy for improving co-catalytic properties of MoS2 and expands the application of Fe3+/PS system for contaminants remediation.

• 单位
  y; 清华大学