Abstract:Copper（Cu）have been extensively studied for electrochemical conversion of carbon dioxide（CO2）into formate，but have a series of problem such as the competing hydrogen evolution reaction （HER）and poor stability. The introduction of another metal into metallic Cu to construct Cu-based alloy has shown great promise in alleviating the problem. However，the complicated synthetic routes severely restrict their practical applications. Herein，this paper reported the galvanic-cell deposition for the rapid synthesis of self-supported CuBi nanodendrites directly grown on graphene covered Cu foil（nCuBi-G/Cu foil）. The host metal Bi could donor electron from Bi to Cu，which enabled superior CO2 reduction performance. nCuBi-G/Cu foil achieved a formate Faradaic efficiency of 95.91% at -0.93 V（vs. RHE）and delivers a stable current density of about 20.1 mA/cm2 with a negligible decay during 20 h of continuous electrocatalysis. Furthermore，it was found that graphene as deposition substrate could accelerate electron transfer，contributing to an excellent activity of CO2 reduction This work provided a novel strategy for the green synthesis of efficient CuBi bimetal catalysts for CO2 reduction and demonstrated the substrate and electronic engineering strategy to improve the CO2 reduction activity.