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-C_product 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.