CO<sub>2</sub> Electroreduction to Formate at a Partial Current Density up to 590 mA mg<sup>−1</sup> via Micrometer‐Scale Lateral Structuring of Bismuth Nanosheets
Dan Wang, Chuangwei Liu, Yaning Zhang, Yaning Zhang, Yanying Wang, Zhenlin Wang, Ding Ding, Yi Cui, Xiangmiao Zhu, Chengsi Pan, Yang Lou, Fengwang Li, Yongfa Zhu, Ying Zhang, Ying Zhang
Abstract
Abstract 2D bismuth nanosheets are a promising layered material for formate‐producing via electrocatalytic CO 2 conversion. However, the commercial interest of bismuth nanosheets in CO 2 electroreduction is still rare due to the undesirable current density for formate at moderate operation potentials (about 200 mA mg −1 ) and harsh synthesis conditions (high temperature and/or high pressure). This work reports the preparation of Bi nanosheets with a lateral size in micrometer‐scale via electrochemical cathodic exfoliation in aqueous solution at normal pressure and temperature. As‐prepared Bi LNSs (L indicates large lateral size) possess high Faradaic efficiencies over 90% within a broad potential window from −0.44 to −1.10 V versus RHE and a superior partial current density about 590 mA mg −1 for formate in comparison with state‐of‐the‐art results. Structure analysis, electrochemical results, and density functional theory calculations demonstrate that the increasing tensile lattice strain observed in Bi LNSs leads to less overlap of d orbitals and a narrower d‐band width, which tuning the intermediate binding energies, and therefore promotes the intrinsic activity.