Enhancement performance of carbon electrode for supercapacitors by quinone derivatives loading via solvent-free method

Activated carbon (AC) from coconut shell, surface area of 764.09 cm2/g, was functionalized with various quinone derivatives (anthraquinone (AQ), 9,10-phenanthrenequinone (PQ) or tetrachlorohydroquinone (TCHQ)) via a sublimation method for supercapacitor application. The properties of modified activated carbons were characterized by X-ray diffraction (XRD), scanning electron microscopy coupled with energy dispersive X-ray (SEM-EDX) spectroscopy, X-ray photoelectron spectroscopy (XPS) and nitrogen adsorption-desorption. The results showed a supercapacitor containing AC modified with 16%wt. AQ achieved higher specific capacitance than other quinone derivatives which performed specific capacitance about 485 F g-1 at a current density of 1.0 A g-1, resistance of 2.25 Ω and exhibited high cyclability which loss specific capacitance of 1.2% after 1000 charge-discharge cycles. The experimental data is in good agreement with the computational results of quinone adsorption on graphene surface; the lowest interaction energy (IE) of -28.0 kcal mol-1 was obtained for AQ loading model. The modified AC successfully prepared by a solvent-free method which could be further developed as low-cost and environmentally friendly electrode materials for high-performance supercapacitors.