Optimizing pre-carbonization temperature in sustainable cow hoof-derived activated carbon for high-performance supercapacitor electrodes

This study focuses on optimizing carbon materials derived from cow hooves (an abundant and sustainable bioresidue) for use as electrodes in supercapacitors, with particular emphasis on the pre-carbonization process prior to chemical activation using environmentally friendly potassium carbonate (K 2 CO 3 ). Pre-carbonization was conducted at varying temperatures (500, 600, and 700 ºC), subsequent chemical activation involved impregnation with K 2 CO 3 at a ratio of 3:1 (activating agent to precursor) and activation at 800 ºC. The resulting activated carbons underwent comprehensive structural and morphological characterization using advanced techniques, including X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Electrochemical performance was evaluated through cyclic voltammetry (CV), galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy (EIS) in a three-electrode configuration. Among the samples, the material pre-carbonized at 600 ºC exhibited the best electrochemical performance, achieving the highest specific capacitance in the group. When incorporated into a symmetric aqueous supercapacitor, this material achieved an impressive specific capacitance exceeding 200 F/g and demonstrated excellent electrochemical stability over prolonged cycles. This research not only establishes cow hoof-derived carbons as a sustainable and efficient material for supercapacitor electrodes but also provides valuable insights into the design of eco-friendly energy storage systems.