Synthesis of tea dregs-derived 3D interconnected honeycomb-like porous activated carbon for supercapacitor applications

Abstract

ABSTRACT Biomass-derived porous activated carbon and their applications as supercapacitor (SC) electrode materials have gained immense research interest owing to their abundance, inexpensive, recyclable, etc. Herein, we report the synthesis of tea dregs-derived 3D interconnected honeycomb-like porous activated carbon (HCAC) via a simple, effective, and inexpensive method for SC applications. Tea dregs waste was activated using NaOH activation with different mass ratios of 1:3, 1:4, and 1:5 under a N2 atmosphere at 800°C for 3.5 h. The scanning electron microscope, energy dispersive X-ray (EDX) spectroscopy, adsorption/desorption isotherm of N2, X-ray diffraction (XRD), FT-IR, and cyclic voltammetry methods were employed to analyze surface morphology, elemental compositions, specific surface area, crystallographic feature, surface functional groups, and electrochemical behavior, respectively. The as-obtained HCAC-3 has a 3D interconnected honeycomb-like porous architecture with high carbon and oxygen contents, achieved the specific surface area of 624 m2/g, amorphous carbon structure, and containing oxygen functional group. The symmetrical SC devices have an optimum specific capacitance of 100 F/g with an optimum energy density of 13.89 Wh/kg at a power density of 50.05 W/kg. This study could provide a good reference for the synthesis of biomass-derived 3D interconnected HCAC and its applications in energy storage devices systems, catalysts, and adsorbents.