Honeycomb porous Pb films with a dendrite-like secondary structure growing along the [100]-axis were prepared by Dynamic Hydrogen Bubble Templating (DHBT) and used for the electroreduction of CO₂. Detailed physicochemical characterization of the porous films revealed that the thickness (up to 70 μm) and electrochemically active surface area (up to 1500 cm²) of the porous Pb films could be tuned through the current density (varied between −1 and −4 A cm⁻²) and deposition time (varied between 3 and 60 s). The electrochemical activity and stability of the electrodes toward the electroreduction of CO₂ were investigated by linear sweep voltammetry and potentiostatic electrolysis in 1 M KHCO₃ electrolyte at standard pressure and room temperature. The formate production was quantified by UV-visible spectrophotometry. The faradaic efficiency for formate was larger than 90% for electrodes with electrochemical surface areas above 500 cm² and it was attributed to an increased fraction of the [100] surfaces. The porous Pb film deposited at −4.0 A cm⁻² and 40 seconds proved to be a highly active and stable electrode, with a partial current density (j_formate) of −7.5 mA cm⁻² and a faradaic efficiency of 97% for formate at an overpotential of −0.99 V after 6 hours of electrolysis.

中文翻译：

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选择性电还原CO ₂形成具有纳米级针状尖端的3D [100] Pb树枝状晶体

通过动态氢气泡模板法（DHBT）制备了沿[100]轴生长的具有树突状二级结构的蜂窝状多孔Pb薄膜，并将其用于CO ₂的电还原。多孔膜的详细理化特性表明，多孔Pb膜的厚度（最大70μm）和电化学活性表面积（最大1500 cm ²）可以通过电流密度（在-1和-4 A之间变化）进行调节。 cm ^-2）和沉积时间（3至60 s之间变化）。通过线性扫描伏安法和恒电位电解在1 M KHCO ₃中研究了电极对CO ₂电化学还原的电化学活性和稳定性。电解液在标准压力和室温下。通过UV-可见分光光度法定量甲酸盐的产生。对于电化学表面积大于500 cm ^2的电极，甲酸的法拉第效率大于90％，这归因于[100]表面分数的增加。事实证明，在-4.0 A cm ^-2和40秒时沉积的多孔Pb膜是高活性且稳定的电极，其部分电流密度（j_甲酸）为-7.5 mA cm ^-2，法拉第效率为甲酸的97％电解6小时后，在-0.99 V的超电势下。