Xiang Qian, Li Fan, Wang Jiale, Chen Wenlong, Miao Qiushi, Zhang Qingfeng, Tao Peng, Song Chengyi, Shang Wen, Zhu Hong, Deng Tao, Wu Jianbo
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, P. R. China.
University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai 200240, P. R. China.
ACS Appl Mater Interfaces. 2021 Mar 10;13(9):10837-10844. doi: 10.1021/acsami.0c20302. Epub 2021 Feb 23.
Electrochemical reduction of CO to valuable chemicals or fuels is critical for closing the carbon cycle and preventing further deterioration of the environment. Here, we discover that by adopting the Zn foil as the substrate, a ZnO two-dimensional sheet array is in situ synthesized on the Zn foil by a facile hydrothermal method. The obtained ZnO sheet array/Zn foil exhibited an outstanding CO reduction performance to CO, which showed the highest Faraday efficiency of 85% for CO at -2.0 V (vs Ag/AgCl) with a current density of 11.5 mA/cm compared with the freestanding ZnO sheets and particles and excellent stability in the 0.1 M KHCO electrolyte. The in situ vertical ZnO sheet array exposed with abundant exposed (11̅00) edge facets can accelerate the electron transfer and improve the number of active sites, which leads to the enhanced reduction performance. Alongside, the density functional theory simulation indicated that the vertical-grown ZnO sheet array possesses lower Gibbs free energy for the CO activation, with a more exposed (11̅00) edge surface of ZnO.
将CO电化学还原为有价值的化学品或燃料对于闭合碳循环和防止环境进一步恶化至关重要。在此，我们发现通过采用锌箔作为基底，通过简便的水热法在锌箔上原位合成了二维ZnO片阵列。所获得的ZnO片阵列/锌箔对CO表现出出色的CO还原性能，在-2.0 V（相对于Ag/AgCl）下对CO的法拉第效率最高可达85%，电流密度为11.5 mA/cm²，与独立的ZnO片和颗粒相比，在0.1 M KHCO₃电解液中具有出色的稳定性。原位垂直的ZnO片阵列暴露有丰富的（11̅00）边缘晶面，可加速电子转移并增加活性位点数量，从而提高还原性能。此外，密度泛函理论模拟表明，垂直生长的ZnO片阵列对CO活化具有较低的吉布斯自由能，且ZnO的（11̅00）边缘表面暴露得更多。
