Exploring electrochemical performance of Zanthoxylum armatum seed-derived activated carbon using phosphoric acid (H3PO4) for sustainable energy storage applications

The escalating environmental concerns stemming from fossil fuel exploitation coupled with global energy demand and technological advancements underscore the urgent need for developing innovative energy storage solutions like supercapacitor. This study aims to address the critical need for advancing energy storage technologies to meet current requirements by utilizing bio-waste materials. In this research work, activated carbon for supercapacitor, as negative electrode materials were synthesized from Zanthoxylum armatum seeds through a multi-step carbonization process at an elevated temperature of 900 °C, utilizing H₃PO₄ as the activating agent (HZAC-900). The crystallinity of the material was examined using X-ray diffraction (XRD) technique, functional groups were identified via Fourier-transform infrared (FTIR) spectroscopy, and morphology was analyzed using Field Emission Scanning Electron Microscopy (FE-SEM). The HZAC-900 sample exhibited a higher surface area of 887.256 m² g⁻¹ as revealed by Brunauer-Emmett-Teller (BET) surface analysis. Furthermore, the chemical state of each element was analyzed using X-ray photoelectron spectroscopy (XPS). Comprehensive electrochemical evaluations, including cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge (GCD) tests, were conducted to assess the material's electrochemical performance. The activated carbon prepared at a carbonization temperature of 900 °C demonstrated a specific capacitance of 132.90 F g⁻¹ at a current density of 0.5 A g⁻¹, emphasizing its exceptional suitability for supercapacitor applications. These findings highlight the potential of Zanthoxylum armatum seed-derived activated carbon as an effective material for advanced energy storage systems, offering a promising avenue for the development of sustainable energy solutions.