Electrochemical reduction of carbon dioxide to formate via nano-prism assembled CuO microspheres

Electrochemical reduction of CO₂ has been demonstrated as one of the promising technologies to reduce the greenhouse effect. In this study, nano-prism assembled hierarchical CuO microspheres (Prism-CuO) were designed and used for CO₂ electroreduction. The Prism-CuO coated gas diffusion electrode showed high activity for CO₂-to-formate conversion with overpotential as low as ∼200 mV, and achieved maximum faradaic efficiency of 65.1% at -1.6 V vs. Ag/AgCl. Moreover, it maintained the stable performance for continuous 20 h of electrolysis. The better performance was mainly attributed to the unique prism feature as it provided abundant corner- and edge-based low-coordinated active reaction sites. These sites could further arouse strong local-electric field to lower the barrier of CO₂ adsorption and motivate CO₂ activation by accelerating charges transfer process. The result implied designing the nano-prism constructed hierarchical framework would be an efficient strategy to develop the advanced electrocatalyst for efficient CO₂ reduction in aqueous solution.