Waste Bovid (Buffalo & Goat) Bone-Derived H₃PO₄-Activated Porous Carbon for Supercapacitor Electrode Applications

Porous activated carbon derived from waste buffalo and goat bones was explored for aqueous supercapacitor electrodes using H₃PO₄ as an activating chemical. Among several prepared samples with impregnation ratios 1:1 – 1:3 and carbonization from 400 °C to 600 °C, buffalo bone-derived carbon (BBAC-2-500) exhibited a higher specific surface area of 1724 m² g⁻¹. Goat bone-derived carbon (GBAC-3-600) showed a surface area of 1119 m² g⁻¹. Raman analysis found slightly higher defect density, and FTIR revealed a greater amount of oxygen bonding functional groups in BBAC-2-500. XRD confirmed that both materials were amorphous, with a minor structural ordering in GBAC-3-600. BBAC-2-500 delivered a specific capacitance of 280 F g⁻¹ in 6 M KOH electrolyte at 1 A g⁻¹ and an energy density (ED) of 14 Wh kg⁻¹ at a power density (PD) of 300 W kg⁻¹. GBAC-3-600 achieved 236 F g⁻¹ and 11.8 Wh kg⁻¹ under the same conditions. The BBAC-2-500 electrode retained 96.87% capacitance after 10,000 cycles and 99.11% coulombic efficiency. These findings demonstrate that the combined effects of precursor selection and activation conditions govern the electrochemical performance of bone-derived carbon electrodes.