Fenton-like reaction enhanced activation of biomass-derived porous carbon for high-performance supercapacitor

Abstract

The rational design of high-performance electrode materials plays a key role in the capacitive performance of supercapacitors. This study presents a novel strategy for the synergistic preparation of biomass-derived porous carbon via a mild Fenton-like reaction pretreatment combined with KOH activation. This strategy reveals the formation mechanism of porous carbon, wherein the pretreatment effectively decomposes the macromolecular structures in biomass, promoting the formation of pore structures and the significant increase of activation sites, thus improving the activation efficiency of KOH. Due to the synergistic effects of pretreatment and KOH activation, the obtained porous carbon material exhibits a remarkable specific surface area of 2801 m² g^–1, and the activation efficiency doubled compared to the unpretreated sample. In a 3 M KOH electrolyte, the optimized porous carbon electrode has a high specific capacitance of 349 F g⁻¹. Furthermore, the assembled symmetric supercapacitor retains a capacitance retention rate as high as 99 % after 70,000 charge-discharge cycles, showing exceptional long-term cycling stability. In addition, the symmetric supercapacitor assembled with the porous carbon in 1 M Na₂SO₄ electrolyte achieves a high energy density of 26.2 Wh kg⁻¹, further verifying the practical application potential of the material. This study not only confirms the positive role of Fenton-like reaction pretreatment in improving the performance of biomass-based porous carbon materials, but also offers a new insight and method for developing high-performance supercapacitor electrode materials.