A carbon quantum dot (CQD) modified-CuZn bimetallic catalyst for efficient electrocatalytic CO2 reduction†

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 dot (CQD)-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 catalyst 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 compared to that of the single ZnO and CuO catalysts. Meanwhile, it also showed good stability within 24 h, and the FE_CO of the catalyst could be maintained above 80% after 24 h, which shows its potential in practical applications.