Unique copper and reduced graphene oxide nanocomposite toward the efficient electrochemical reduction of carbon dioxide

The electrochemical reduction of CO(2) to useful chemicals and fuels has garnered a keen and broad interest. Herein, we report a unique nanocomposite consisting of Cu nanoparticles (NPs) and reduced graphene oxide (rGO) supported on a Cu substrate with a high catalytic activity for CO(2) reduction. The nanocomposite was optimized in terms of the composition of Cu NPs and rGO as well as the overall amount. A gas chromatograph was employed to analyze the gaseous products, whereas a chemical oxygen demand (COD) method was proposed and utilized to quantify the overall liquid products. The optimized nanocomposite could effectively reduce CO(2) to CO, HCOOH and CH(4) with a Faradaic efficiency (FE) of 76.6% at −0.4 V (vs. RHE) in a CO(2) saturated NaHCO(3) solution. The remarkable catalytic activity, high FE, and excellent stability make this Cu-rGO nanocomposite promising for the electrochemical reduction of CO(2) to value-added products to address the pressing environmental and energy challenges.