Graphene-based synthetic fabric cathodes with specific active oxygen functional groups for efficient hydrogen peroxide generation and homogeneous electro-Fenton processes

The development of a novel and versatile cathode, identification of catalytic active sites, and targeted modification of the cathode with active species represent potential development trends for electrochemical hydrogen peroxide (H2O2) generation and its electro-Fenton applications. This work is the first study of a 3D reduced graphene oxide synthetic fabric (rGOSF) cathode with sufficient electrocatalytic activity for H2O2 generation. A multi-step reduction strategy was proposed to tailor the types of oxygen functional groups on rGOSF. The subsequent H2O2 electrochemical generation performance demonstrates that active sites are derived from carboxyl groups. Density functional theory (DFT) calculations confirm the important role of carboxyl groups for oxygen reduction to generate H2O2. A carboxyl-rich functional molecule was then selected to develop the active species-modified rGOSF cathode via a wet co-spinning assembly. The resultant carboxyl-functionalized rGOSF exhibits significantly enhanced activity for H2O2 generation, as well as efficient removal of typical organic pollutants via the homogeneous electro-Fenton process.