Indium doped bismuth subcarbonate nanosheets for efficient electrochemical reduction of carbon dioxide to formate in a wide potential window

Electrochemical carbon dioxide (CO2) reduction reaction (E-CO2RR) to formate with high selectivity driven by renewable electricity is one of the most promising routes to carbon neutrality. Herein, we developed a novel indium (In)-doped bismuth subcarbonate (BOC) nanosheets (BOC-In-x NSs) through transformation of In-doped bismuth (Bi) nanoblocks (Bi-In-x NBs). The BOC-In-0.1 NSs achieved a maximum Faraday efficiency of formate (FEformate) nearly 100% with high stability (22 h) and an appreciable average FEformate of 93.5% in a wide potential window of 450 mV. The experimental and theoretical calculations indicate that the incorporation of In into BOC nanosheets enhanced the adsorption of CO2 and the intermediates during the process of E-CO2RR, and reduced the energy barrier for the formation of formate.