100 Gram-scale organic-free synthesis of Bi2O2CO3 nanosheets for highly selective formate production in CO2 electroreduction

Abstract

In the realm of CO₂ electrochemical reduction, Bi₂O₂CO₃ nanosheets have garnered attention for their ability to selectively produce formate. However, as CO₂ electroreduction technologies advance toward industrial applications, a scalable and green synthesis method is urgently needed. Our research leverages three common Bi-based inorganic salts—BiCl₃, Bi₂(SO₄)₃, and Bi(NO₃)₃—as precursors to develop a straightforward process of hydrolysis followed by anion exchange. This method produces high yields of Bi₂O₂CO₃ nanosheets without the need for organic solvents or external heating, even at a large scale of ∼100 grams, ensuring both sustainability and cost-efficiency. The resulting nanosheets achieved faradaic efficiencies exceeding 90% across a wide range of potentials for formate production. The combination of innovative synthesis and effective CO₂ conversion underscores the potential of Bi₂O₂CO₃ for industrial-scale applications in sustainable energy and chemical production.