Electrochemical CO2 fixation in molten salts: A pathway towards the fabrication of exceptional carbon-based materials for pollutant removal

Carbon-based materials have been widely applied for pollutant removal relying on their rich pore structure, functional groups, chemical stability, and expandability. However, the traditional manufacturing process of carbon materials based on organic compounds pyrolysis is high energy-consuming and high-emission, which is not conducive to addressing the climate crisis and achieving the goal of carbon neutrality. Molten salt electrolysis technology enables the direct capture and reduction of CO2 to produce solid carbon, resulting in significant environmental benefits while achieving carbon emissions reduction. The molten salt also has a purification function, enabling the production of high-purity carbon materials. The kinetics of the electrochemical reduction process can be easily controlled, and the co-reduction of multiple elements provides convenience for the in-situ optimization of carbon material structure and the expansion of its applications. Therefore, this review focuses on the thermodynamics & kinetics processes of molten salt capture and electrochemical reduction of CO2 to prepare carbon materials. It further reviews the recent research progress on the preparation of carbon materials for pollutant removal based on molten salt electrochemical processes for the first time. Finally, we analyze the advantages and challenges of the current molten salt electrochemical processes and offers prospects for future research directions.