Electrochemical carbon dioxide reduction reaction (CORR) is an effective approach to capture CO and convert it into value-added chemicals and fuels, thereby reducing excess CO emissions. Recent reports have shown that copper-based catalysts exhibit excellent performance in converting CO into multi-carbon compounds and hydrocarbons. However, theselectivityto the couplingproductsispoor. Therefore, tuningCO-reductionselectivitytoward Cproductsover Cu-based catalyst is one of the most important issues in CORR. Herein, we prepare a nanosheet catalyst with interfaces of Cu/Cu. The catalyst achieves Faraday efficiency (FE) of C over 50% in a wide potential window between - 1.2 V to - 1.5 V versus reversible hydrogen electrode (vs. RHE). Moreover, the catalyst exhibits maximum FE of 44.5% and 58.9% towards CH and C, with a partial current density of 10.5 mA cm at - 1.4 V. Density functional theory (DFT) calculations show that the interface of Cu/Cu facilitates CC coupling to form C products, while inhibits COconversion toCproducts.