The advancement of cost-effective and selective electrocatalyst towards CO2 to CO conversion is crucial for renewable energy conversion and storage,thus to achieve carbon-neutral cycle in a sustainable manner.In this communication,we report that Cu2Sb decorated Cu nanowire arrays on Cu foil act as a highly active and selective electrocatalyst for CO2 to CO conversion.In CO2-saturated 0.1 M KHCO3,it achieves a high Faraday efficiency (FE) of 86.5％ for CO,at-0.90 V vs.reversible hydrogen electrode (RHE).The H2/CO ratio is tunable from 0.08:1 to 5.9:1 by adjusting the potential.It is worth noting that HCOO-product was totally suppressed on such catalyst,compared with Sb counterpart.The improving selectivity for CO could be attributed to the bimetallic effect and nanowire arrays structure.