Stimulating the Intrinsic Activities of the MoS2 Nanosheet Coated on S,N-Graphene for Efficient Membrane Electrofiltration

Strategies for harmonizing an active site and electron transportation of a graphene-based composite membrane are crucial for their application in electrofiltration treatment of organic wastewater. In this study, a heterogeneous MoS2-coated S,N-graphene (SNG) membrane (O-MoS2@SNG) was developed through a facile strategy. The electrochemical performance of O-MoS2@SNG was optimized with 7.3 wt % of MoS2 loading, exhibiting superior electrocatalytic performance (>90%) of bi-sphenol A with a large permeation volume in the online electrofiltration system. Spectroscopic structure characterization and macroscopic experimental results reveal that the Mo-O-C heterointerface was generated to bond the MoS2 nanosheet with the SNG substrate, and it substantially facilitated the electron transfer in MoS2@SNG as compared with the Mo-C interface. Moreover, Mo(VI)-O on the edge of MoS2 in O-MoS2@SNG can serve as the active center by the critical MoIV/MoVI redox couple, which would contribute to the electrochemical activities. Density functional theory (DFT) calculations also confirm that the uncoordinated Mo was the active site with optimal building energy for BPA degradation, and the Mo-O-C heterointerface facilitated electron transfer to improve electrochemical degradation.

Automated summary

In this study, a heterogeneous MoS2-coated S,N-graphene (SNG) membrane (O-MoS2@SNG) was developed through a facile strategy. The electrochemical performance of O-MoS2@SNG was optimized and exhibited superior electrocatalytic performance (>90%) of bi-sphenol A with a large permeation volume in the online electrofiltration system.