Carbon quantum dots (CQDs) modified-CuZn bimetallic catalyst for efficient electrocatalytic CO2 reduction

Abstract

Abstract The development of highly selective and active catalysts for electrochemical carbon dioxide reduction (CO2ER) is essential for its practical application. In the current work, carbon quantum dots (CQDs)-modified CuZn bimetallic electrodes were successfully synthesized by a one-step hydrothermal method. The obtained catalysts were thoroughly characterized and the performance of the catalysts was compared using LSV, EIS, CV, ESCA, Tafel, and DFT calculations. It is found that the Cu1Zn2 catalysts with 1.5 wt.% CQDs exhibited the highest Faraday efficiency (FE, 92.5%) for CO at 1.3 V (vs. RHE), and the current densities were enhanced by a factor of 5.21 and 4.13 times compared to the single ZnO and CuO catalysts. Meanwhile, it also showed good stability within 24 h, and the FECO of the catalyst could be maintained above 80% after 24 h, which shows its potential in practical applications.