Hydrothermal Fabrication of Low-Dimensional CuO Nanosheets for Enhancing Carbon Reduction Product Selectivity

The electrocatalytic reduction of CO2 to C2 products, driven by renewable electricity, represents a promising approach for storing intermittent renewable energy. A major challenge, however, lies in the difficulty of suppressing the competing hydrogen evolution reaction (HER), which significantly lowers the selectivity toward C2 products and diminishes the overall efficiency of the CO2 reduction systems. Here, we report a strategy for designing metal-based catalysts through precise regulation of the hydrothermal reaction temperature, thereby enhancing the efficiency of the conversion of CO2 to C2 products. The catalyst of CuO at 200 °C shows a CO2-to-C2 Faradaic efficiency of 58.6% and a CO2-to-Cproduct Faradaic efficiency of 70% at −1.4 V vs RHE. Our work provides foundational insight into the crucial role of catalyst morphology in enhancing performance in CO2 electrolysis, facilitating the rational development of highly efficient CO2 reduction catalysts.