Nitrogen-Doped Bismuth Nanosheet as an Efficient Electrocatalyst to CO(2) Reduction for Production of Formate

Electrochemical CO(2) reduction (CO(2)RR) to produce high value-added chemicals or fuels is a promising technology to address the greenhouse effect and energy challenges. Formate is a desirable product of CO(2)RR with great economic value. Here, nitrogen-doped bismuth nanosheets (N-BiNSs) were prepared by a facile one-step method. The N-BiNSs were used as efficient electrocatalysts for CO(2)RR with selective formate production. The N-BiNSs exhibited a high formate Faradic efficiency (FE(formate)) of 95.25% at −0.95 V (vs. RHE) with a stable current density of 33.63 mA cm(−2) in 0.5 M KHCO(3). Moreover, the N-BiNSs for CO(2)RR yielded a large current density (300 mA cm(−2)) for formate production in a flow-cell measurement, achieving the commercial requirement. The FE(formate) of 90% can maintain stability for 14 h of electrolysis. Nitrogen doping could induce charge transfer from the N atom to the Bi atom, thus modulating the electronic structure of N-Bi nanosheets. DFT results demonstrated the N-BiNSs reduced the adsorption energy of the *OCHO intermediate and promoted the mass transfer of charges, thereby improving the CO(2)RR with high FE(formate). This study provides a valuable strategy to enhance the catalytic performance of bismuth-based catalysts for CO(2)RR by using a nitrogen-doping strategy.