Lanthanide dopant-driven Bi-O covalency modification for optimizing microenvironment and promoting CO₂ electrolysis...

The performance of CO₂ reduction reaction (CO₂RR) can be enhanced by regulating the microenvironment of the gas-liquid-solid interface. However, achieving excellent CO₂RR performance necessitates that the adsorption strength of CO₂ molecules and reaction intermediates, as well as interface behaviour of H₂O, are precisely regulated. This regulation is implemented to overcome the limitations of CO₂ molecular mass transfer power, optimise the adsorption strength of the intermediate, and adjust the surface density of the *H adsorbent. In this study, an Sm-doped Bi₂O₂CO₃ nanosheet with abundant Bi^δ+ (0 < δ < 3) is prepared through lanthanide doping to regulate the electronic structure strategy, thereby successfully manipulating the microenvironment of the gas-liquid-solid three-phase interface. In an H-type cell, the Sm-doped Bi₂O₂CO₃ electrocatalyst demonstrates a remarkable Faraday efficiency for formate generation, exceeding 90% over a wide potential range from -1.0 to -1.4 V (versus RHE). This study provides novel insights into establishing a favourable microenvironment at the gas-liquid-solid interface and promoting CO₂RR efficiency.