Electron distribution regulating of nonmetal doped monolayer g-GaN for enhanced electrocatalytic CO2 reduction

Abstract

Exploring inexpensive electrocatalysts that can efficiently and selectively convert CO2 into hydrocarbon fuels is important to promote carbon neutrality and solve the energy crisis. Current electrocatalysts, such as Cu-based alloys, single-atom catalysts, and dual-atom catalysts, use the d states of metal in the electrocatalytic CO2 reduction reaction. Inspired by this, this work studies CO2 reduction reaction from another approach. Herein, using first principles study, we systematically investigate the prospect of nonmetal (B, C, O and F) doped monolayers g-GaN as electrocatalysts for the CO2 reduction reaction. We found that nonmetal doping can effectively regulate the electron distribution and p-band center of the active center (N site), which can adjust the initial adsorption, activation degree, charge transfer amount of CO2, and promote the formation of intermediates. Interestingly, B and C doped systems have better catalytic activity for CH4, with limiting potentials of −0.61 and −0.53 V, respectively. More importantly, F doped system has higher activity and selectivity for CH3OH production and inhibit competitive HER, with lower limiting potentials of −0.60 V. This study provides a new theoretical basis for the design and screening of electrocatalysts with high activity and product selectivity using nonmetal as the active site.