Porous Nitrogen-Doped Nb₂C Nanosheets for Electrocatalytic ORR to Selectively Produce H₂O₂

The two-electron pathway in the oxygen reduction reaction (ORR) represents an efficient and environmentally friendly approach for hydrogen peroxide (H₂O₂) production. Among various types of potential catalysts, MXene have garnered significant attention due to their outstanding electrical conductivity, abundant edge active sites, and low costs. In this study, we successfully synthesize porous N-doped Nb₂C nanosheets (N-Nb₂C) via a room-temperature ammonia etching method and investigate their ORR performance toward the formation of H₂O₂. The doping of nitrogen effectively modulates the electronic structure of Nb₂C nanosheets, while the abundant surface pores formed during ammonia etching facilitate the ORR process. Hence, the electrocatalytic performance of N-Nb₂C nanosheets is significantly improved, demonstrating excellent long-term stability and durability. Notably, in rotating ring-disk electrode (RRDE) tests, the N-Nb₂C catalyst achieves a remarkable H₂O₂ yield of 86.8%, highlighting its potential for selective H₂O₂ production through electrocatalytic ORR. Our findings suggest that N-doped Nb₂C holds great promise for applications in two-electron oxygen reduction for H₂O₂ synthesis.