Electroreduction of CO₂ into value-added fuels has been considered as a promising technology to mitigate the CO₂-invoked greenhouse effect. However, the poorer selectivity and lower stability of electrocatalysts still impede its development. In this work, we prepared a nano-dendrite Bi film electrode by simple one-step electrodeposition method. The Bi (1200) (deposition time of 1200s) exhibited a superior catalytic activity in a wide potential towards CO₂-to-formate conversion and acquired the maximum faradaic efficiency (FE_formate) of 97.5 % at –1.5 V vs Ag/AgCl. More encouragingly, it showed an excellent stability as the FE_formate maintained ∼ 90 % over 108 h of electrolysis which outperformed most of the reported Bi-based electrodes. The notable performance was mainly attributed to the thorn-like structure which afforded massive active sites. Meantime, Bi-O structure on oxide-derived Bi was beneficial for CO₂ adsorption and activation with accelerated interfacial charge transfer process. Moreover, the well-preserved electrode morphology and Bi-O component enabled its longer stable service life. This result implied Bi film electrode would be a promising candidate for efficient CO₂ electroreduction.

CO的电还原₂成有附加值的燃料已被认为是有前途的技术，以减轻CO ₂ -invoked温室效应。但是，电催化剂的较差的选择性和较低的稳定性仍然阻碍了它的发展。在这项工作中，我们通过简单的一步电沉积方法制备了纳米树枝状Bi膜电极。Bi（1200）（沉积时间为1200s）在对CO ₂转化为甲酸的广泛潜力中显示出优异的催化活性，并且在相对于Ag / AgCl的–1.5 V下获得了97.5％的最大法拉第效率（FE_甲酸）。更令人鼓舞的是，FE_甲酸酯具有出色的稳定性。在108小时的电解过程中保持了约90％的性能，优于大多数报道的Bi基电极。显着的性能主要归因于刺状结构，该结构提供了大量的活性位点。同时，在氧化物衍生的Bi上的Bi-O结构通过加速界面电荷转移过程有利于CO _2的吸附和活化。此外，保存完好的电极形态和Bi-O成分使其具有更长的稳定使用寿命。该结果暗示Bi膜电极将是有效CO ₂电还原的有希望的候选者。