Abstract:SnO2 is an efficient electrocatalyst for CO2 reduction to formic acid. However, the preparation of SnO2 electrodes is relatively complex and typically requires the addition of conductive agents and binders to improve the electrode's conductivity and stability. These additional components frequently diminish the catalytic efficiency of SnO2 electrodes, thereby impacting their performance in CO2 reduction reactions. Therefore, how to prepare SnO2 electrodes with high catalytic activity that does not rely on added conductive agents and binders has become a key research challenge. To address this challenge, this study employs a simple electrodeposition method to fabricate SnO2/Cu electrodes. This method avoids the addition of inactive components and successfully achieves a high-performance CO2 reduction process for formic acid production. The SnO2/Cu electrodes prepared by electrodeposition exhibite good electrochemical performance and stability. First, to investigate the effect of deposition current density on the electrocatalytic CO2 reduction performance of the electrodes, SnO2/Cu electrodes were prepared with three different deposition current densities: -3, -5 and -7 mA/cm2. The SEM and ECSA analysis results reveal that the SnO2/Cu electrode with a deposition current density of -5 mA/cm2 has a uniformly distributed SnO2 nanosheet structure on its surface, exhibiting higher surface roughness. This structure helped expose more active sites and increased the electrode's specific surface area.The LSV and EIS analysis results show that the SnO2/Cu electrode at a deposition current density of -5 mA/cm2 exhibits better hydrogen evolution suppression and a faster charge transfer rate, which is beneficial for accelerating the sluggish CO2 reduction reaction kinetics. CO2 reduction experiments show that at a potential of -1.8 V(vs. SCE), the optimal electrode achieves a Faradaic efficiency of 80.48% for formic acid production, with a production rate of 109.96 μmol/(h?cm2).The electrode maintained a high Faradaic efficiency (>72%) over a wide potential range from -1.7 V(vs. SCE) to -1.9 V (vs. SCE), indicating its good catalytic stability and adaptability. In conclusion, this study provides a simple and effective preparation method, using electrodeposition to fabricate SnO2/Cu electrodes, which avoids the addition of inactive components and achieves efficient, stable CO2 reduction to formic acid. This study not only explores the catalytic mechanisms of SnO2 electrodes in depth but also provides valuable insights for the design and optimization of efficient and stable SnO2 electrodes.