Structural regulation of carbon materials through hydrothermal mixing of biomass and its application in supercapacitors

Using low-cost biomass to effectively prepare porous carbon with appropriate structural properties for supercapacitor electrodes materials remains significant. Herein, we report an efficient method to prepare hierarchical porous carbon using a mixing biomass carbon precursor by sugarcane bagasse and hydroxyapatite from beef bone powder, following with hydrothermal carbonization and KOH activation. The resulting carbon material presents a high specific surface area of 3103.14 m2 g−1, a large pore volume of 1.91 cm3 g−1, and appropriate porosity. Benefiting from these features, the as-assembled symmetrical supercapacitor exhibits high specific capacitance of 397.9 F g−1 (at 0.5 A g−1) in 6 M KOH electrolyte. Moreover, in 1 M Na₂SO₄ electrolyte, it also exhibits high energy density of 23.2 Wh kg−1 at a power density of 874 W kg−1. The enhanced capacitive performance demonstrates that the mixing biomass carbon precursor is desirable to synthesize porous carbons for energy storage. •Maillard reaction modification method to synergistically modify the surface of carbon materials.•BS-1-0.9 has a surface area of 3103.14 m2 g-1 and a porosity of 1.91 cm3 g−1.•The specific capacitance of the three-electrode BS-1-0.9 material is 397.9 F g-1 (0.5 A g-1/KOH).•Quantum chemical analysis to explore mechanisms of material properties and performance enhancement.