Nb2CTX MXenes functionalized Co-NC enhancing electrochemical H2O2 production for organics degradation

Cobalt-dispersed nitrogen-doped carbon nanotubes supported on oxygen-terminated Nb2CTx MXenes (Co-NC/MXenes) are successfully constructed, in which ZIF-67 are in-situ grown on Nb2CTx and then converted to Co-NC followed a pyrolysis process. The introduction of oxygen-terminated Nb2CTx MXenes can effectively regulate the structure of Co-NC and induces a strong interaction between Nb2CTx and Co-NC, promoting H2O2 electrosynthesis via two-electron (2e(-)) oxygen reduction reaction (ORR) with high selectivity. Moreover, the assembled device with Co-NC/MXenes as cathode enables an accumulated H2O2 concentration of 4.8 wt% even under natural air diffusion. When combined with the dual-cathode system, the device achieves excellent total organic carbon (TOC) removal towards organic dyes (50 mg L-1) and sulfamethoxazole (20 mg L-1). This work provides a direction for the precise construction of 2e(-) ORR catalysts and expands an emerging application of the dual-cathode technique.