Oxygen vacancy stabilized Bi 2 O 2 CO 3 nanosheet for CO 2 electroreduction at low overpotential enables energy efficient CO‐production of formate

Abstract Bismuth‐based electrocatalysts are promising candidates for electrochemical CO 2 reduction to formate attributing to the accelerated formation of *OCHO intermediate, while the high‐energy consumption remains a major challenge for practicability. Herein, we present the ultrathin Bi 2 O 2 CO 3 nanosheets with abundant oxygen vacancy ( Vo ‐BOC‐NS) reconstructed from S, N‐co‐doped bismuth oxides that can act as durable electrocatalyst for CO 2 ‐to‐formate conversion with faradic efficiency (FE formate ) of >95%, partial current density of 286 mA cm −2 with energy efficiency of 73.8% at −0.62 V (vs. RHE) and low overpotential of 200 mV in a flow electrolyzer. The theoretical calculations decipher that the oxygen vacancy can optimize *OCOH adsorption/desorption for the accelerated conversion kinetics. The pair‐electrosynthesis tactic of formate co‐production can enable a superior FE formate of >90% at wide cell voltage of 2–3.3 V and total yield rate of 3742 μmol cm −2 h −1 at 3.3 V, suggesting great potential for future industrialization. image