SnO₂-Modified Two-Dimensional CuO for Enhanced Electrochemical Reduction of CO₂ to C₂H₄

Electrochemical reduction of CO₂ was a widespread method for CO₂ conversion into valuable chemical fuel. C₂H₄ is an important product from CO₂ reduction. However, conversion of CO₂ into the hydrocarbon C₂H₄ faced large energy barriers. Herein, we, for the first time, achieve a high efficiency for electrochemical conversion of CO₂ to C₂H₄ on a tin-modified CuO. By modifying with Sn, we obtained a related low onset potential of C₂H₄ as positive as -0.8 V versus RHE and a high Faradaic efficiency of C₂H₄ as high as 22% at -1.0 V (vs RHE). According to density functional calculation, the Sn dopant mainly enriched the electron density of CuO, while it was electron-poor in the Sn dopants. The rate of CO₂ reduction can be enhanced on Cu nanosheets with higher electron density. We believed that this work would promote the development of two-dimensional catalysts for CO₂ conversion and deepen the understanding of doping on CO₂ reduction.