A scalable surface nanoarchitectonics approach for melaleuca bark-derived biochar: Rapid PFOA removal and superior supercapacitor performance

Based on the principles of sustainable development, the porous carbon material with a hierarchical structure derived from Melaleuca bark was developed and applied in environmental pollution control and energy storage. The Melaleuca bark-derived porous carbon material (MBC x ) is prepared using a scalable surface modification strategy that is a one-step carbonization and activation process. MBC 1 displays a hierarchically micro/mesopore structure with an impressive specific surface area (1956.72 m 2 g −1 ) and a substantial pore volume (1.04 cm 3 g −1 ). It retains the fibrous tubular structure of the precursor while forming interconnected mesoporous structures. As absorbent, the maximum adsorption capacity for perfluorooctanoic acid (PFOA) of MBC 1 is 1702.12 mg/g. MBC 1 shows excellent stability and reusability, with high selectivity and removal rates for PFOA in actual fluorine-containing wastewater. MBC 1 tends to adsorb fluorine atoms compounds with a high degree of fluorination and a greater number of fluorine atoms, suggesting the dominant contribution of hydrophobic interactions. However, polyfluorinated PFAS, in which hydrogen atoms replace fluorine in the perfluorinated structure, generally exhibit reduced adsorption. For energy storage, MBC 1 exhibits efficient charge transfer and ion diffusion properties, making it suitable as an electrode material for supercapacitors. The button-type symmetric supercapacitor based on MBC 1 shows excellent electrochemical performance, with a specific capacitance reaching 230.6F g −1 at a current density of 0.5 A g −1 . This powerful surface engineering strategy offers a promising solution to environmental challenges, while contributing to the advancement of clean energy technologies.