Recrystallization-mediated loofah sponge-derived carbon with mesopore dominance for supercapacitor

This study presents a novel strategy for filling the three-dimensional porous structure of the loofah sponge with trehalose to fabricate more structure within and on the surface of the loofah fibers. The trehalose filling and subsequent KOH activation collaboratively tailor the pore structure, significantly enhancing mesoporosity and specific surface area. The optimized loofah-trehalose carbon exhibits a superior pore structure characterized by a higher specific surface area (3188.54 m 3  g −1 ), larger total pore volume (1.65 cm 3  g −1 ), and an increased average pore size (2.38 nm) compared to the trehalose-free sample. This structural advantage contributes to its exceptional electrochemical performance: a high specific capacitance of 319.0 F g −1  at 1 A g −1 in a three-electrode system and 308.8 F g −1  at 0.1 A g −1 in a symmetric supercapacitor. Notably, the device demonstrates outstanding cycling stability with 104.3 % capacitance retention after 10,000 cycles and reduced equivalent series resistance. This work provides a sustainable and effective pore-regulation method for developing high-performance biomass-derived carbon materials.