The electroreduction of CO₂ to formate is of significant interest due to its potential for sustainable fuel and chemical production. Hollow fiber electrodes, which integrate gas diffusion and catalytic layers, offer structural advantages. These advantages enhance gas–solid–liquid-phase reactions, making them particularly beneficial for CO₂ electroreduction. This work reports a copper–bismuth alloy hollow fiber with a nanostructured surface, designed with specific metal ratios and transformed into a sulfur surface-modified copper–bismuth alloy hollow fiber (Cu₇S₄–CuBi HF) electrode with nanoflower structures. CO₂-penetration mode enhances formate current density and Faradaic Efficiency (FE) while suppressing the hydrogen evolution reaction (HER), due to the fiber’s unique gas transport. The nanoflower morphology increases the electrochemical active surface area, boosting current densities. This design achieved a formate FE of 91.27% at −0.9 V vs RHE and a current density of 80.12 mA cm^–2, outperforming many existing Cu@Bi electrocatalysts. This success is due to the innovative surface design and the distinct structural features of the hollow fiber electrodes.

中文翻译：

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使用纳米粗糙化 Cu-Bi 合金中空纤维电极将 CO2 高效还原为甲酸盐


由于 CO 2 在可持续燃料和化学品生产方面的潜力，将 CO₂ 电还原为甲酸盐具有重大意义。中空纤维电极集成了气体扩散层和催化层，具有结构优势。这些优点增强了气-固-液反应，使其特别有利于 CO₂ 电还原。这项工作报道了一种具有纳米结构表面的铜铋合金中空纤维，该纤维设计具有特定的金属比例，并转化为具有纳米花结构的硫表面改性铜铋合金中空纤维 （Cu₇S₄–CuBi HF） 电极。由于光纤独特的气体传输，CO₂ 穿透模式提高了甲酸盐电流密度和法拉第效率 （FE），同时抑制了析氢反应 （HER）。纳米花形态增加了电化学活性表面积，提高了电流密度。与 RHE 相比，该设计在 −0.9 V 下实现了 91.27% 的甲酸盐 FE，电流密度为 80.12 mA cm^–2，优于许多现有的 Cu@Bi 电催化剂。这一成功归功于中空纤维电极的创新表面设计和独特的结构特征。