Controllable Synthesis of Leaf‐Like CuO Nanosheets for Selective CO2 Electroreduction to Ethylene

Abstract The carbon dioxide reduction reaction (CO 2 RR) driven by renewable electricity is a promising way to tackle the CO 2 emission woes and recycle use of CO 2 . The synthesis of electrocatalysts with high activity and selectivity for CO 2 RR to ethylene remains a great challenge. Herein, leaf‐like CuO nanosheets are fabricated in situ on nitrogen‐doped graphene (NG) by using a novel reduction‐oxidation‐reconstruction process. When used as a catalyst for the CO 2 RR in 0.1 M KHCO 3 , a high faradaic efficiency of approximately 30 % for ethylene with an ultra‐high ethylene/methane ratio of 190 was achieved at −1.3 V vs. the reversible hydrogen electrode. The SEM and TEM images confirm the leaf‐like CuO nanosheets display high‐curvature structures, while multiple distinguished grain boundaries constructed by CuO(110) and CuO(111) planes are verified by HRTEM. For the first time, we present a facile method to combine the high‐curvature structure and the grain boundary to enhance the selectivity of the CO 2 RR to ethylene over a CuO catalyst.