Facile synthesis of MnO2 nanorods grown on porous carbon for supercapacitor with enhanced electrochemical performance

Novel MnO 2 -doped holey carbon materials were obtained by an efficient and facile synthetic method using chitosan, potassium hydroxide and potassium permanganate as the raw materials. The carbon framework with high specific surface area was derived from chitosan by carbonization and activation approach, afterwards, MnO 2 nanorods were grown on the surface of porous carbon by one-step agitation method and the MnO 2 -doped holey carbon material was obtained. The scanning electron microscopy, energy-dispersive X-ray, transmission electron microscopy , X-ray diffraction, N 2 adsorption-desorption measurements, Raman spectroscopy and X-ray photoelectron spectroscopy were employed to analyze the physicochemical characteristics of the MnO 2 -doped holey carbon materials. The electrochemical performance of these materials displayed well through relative tests including cyclic voltammetry , galvanostatic charge-discharge, and electrochemical impedance spectroscopy measurements in 6.0 M KOH solution. Especially, this as-obtained electrode material with the optimum ratio presented a high gravimetric capacitance (460F g −1 at 0.2 A g −1 ) and exceptional capacitance reservation (91.67% at 10 A g −1 over 10,000 cycles) in the three-electrode system with 6.0 M KOH solution as the electrolyte.