Direct Conversion of Greenhouse Gas CO₂ into Graphene via Molten Salts Electrolysis

Producing graphene through the electrochemical reduction of CO₂ remains a great challenge, which requires precise control of the reaction kinetics, such as diffusivities of multiple ions, solubility of various gases, and the nucleation/growth of carbon on a surface. Here, graphene was successfully created from the greenhouse gas CO₂ using molten salts. The results showed that CO₂ could be effectively fixed by oxygen ions in CaCl₂-NaCl-CaO melts to form carbonate ions, and subsequently electrochemically split into graphene on a stainless steel cathode; O₂ gas was produced at the RuO₂-TiO₂ inert anode. The formation of graphene in this manner can be ascribed to the catalysis of active Fe, Ni, and Cu atoms at the surface of the cathode and the microexplosion effect through evolution of CO in between graphite layers. This finding may lead to a new generation of proceedures for the synthesis of high value-added products from CO₂, which may also contribute to the establishment of a low-carbon and sustainable world. Gr-aph-een Planet: Graphene is successfully produced through the electrochemical reduction of CO₂ via molten salts electrolysis. The process requires good control of kinetics, such as diffusivities of multiple ions, solubility of various gases, and the nucleation/growth of carbon on a surface, and may lead to a new generation of procedures for the synthesis of high value-added products from CO₂, contributing to the establishment of a low-carbon and sustainable world.