Nitrogen-enriched waste medium density fiberboard-based activated carbons as materials for supercapacitors

Nitrogen-enriched activated carbons were prepared from waste medium density fiberboard base using K2CO3 as an activating agent for electrochemical capacitors. The effect of different temperatures of carbonization (300, 400, 500, and 600 °C) and the influence of the sequence of activation process (a mass K2CO3/coke ratio of 3, temperature of 800 °C and the activation time 1 h) on the electrochemical performance have been investigated. All of the samples were characterized in terms of surface chemical composition by elemental analysis and X-ray photoelectron spectroscopy, porosity by N2 sorption at 77 K, surface area by Brunauer–Emmett–Teller measurement. Electrochemical behavior as electric double-layer capacitors was determined using galvanostatic, voltammetric charge/discharge, specific capacitance values versus current densities, and impedance spectroscopy techniques in a 7 mol L−1 KOH aqueous solution. A maximum value of specific capacitance of 230 F g−1 was achieved for the sample carbonized at 400 °C. The good electrochemical performance of the activated carbon was ascribed to high surface area, wide pore size distribution, and the presence of nitrogen functional groups.

► Supercapacitors have attracted much attention. Porous carbons are more suitable for supercapacitors.
► Re-using waste medium density fiberboard materials is desired.
► The production of activated carbon for supercapacitors from wastes is possible.