Clean Synthesis of Bismuth Porous Nanosheets for Efficient CO₂ Electroreduction

Bismuth porous nanosheets (Bi PNSs) were synthesized via a three-step process in the absence of any surfactants and templates. As a catalyst for electrochemical CO2 electroreduction, Bi PNSs show high selectivity to formic acid with the maximum Faraday efficiency of 95.31% and maintain more than 80% Faraday efficiency over a wide voltage range of 1100 mV. The excellent performance of Bi PNSs was found to originate from the abundant kink sites on the pore walls, which have appropriate affinity to intermediates and reduce the energy barriers for CO2 electroreduction. Our work demonstrates that a clean synthetic route is advantageous to the growth of a unique nanostructure that possesses high catalytic activity.