Three-dimensional porous carbon frameworks derived from mangosteen peel waste as promising materials for CO₂ capture and supercapacitors

Business costs, environmental and energy concerns have increased interest in biomass materials for the production of porous carbon materials, especially as solid-state adsorbents for CO₂ capture or as electrode materials for supercapacitors. We put forward an efficient and scalable approach to convert mangosteen peel (MP) waste into three-dimensional microporous carbon frameworks (3D-MP-CFW) for effective CO₂ capture and supercapacitors. The MP waste is first subjected to a controllable hydrothermal treatment in alkaline solution and then a carbonization process. The resultant optimal carbon sample possesses a high surface area up to 1270 m² g^-1 and abundant micropores with fine micropore sizes below 1 nm. The typical sample has a well-tailored open 3D macroporous interconnected network structure, exhibiting an outstanding CO₂ capture recyclability and high CO₂ capture capacities of 6.93 and 4.77 mmol g^-1 at 0 °C and 25 °C (1 bar), respectively. Simultaneously, benefiting from its high surface area and 3D interconnected porous structure, this optimal sample also exhibits a good supercapacitance performance with the specific capacitance of 240 F g^-1 (in 6 M KOH, at 1 A g^-1) in a three-electrode system. Our simple preparation method presents an efficient way to make promising carbon materials for high-performance CO₂ capture and supercapacitors.