An activated carbon derived from tobacco waste for use as a supercapacitor electrode material

A tobacco-derived activated carbon (TAC) was prepared from tobacco waste using KOH activation with a KOH/tobacco carbon mass ratio of 3 at 800 °C for 1 h, and was used as an electrode material for a supercapacitor. The tobacco waste was hydrothermally treated in a 10%(v/v) HCl solution to remove metallic impurities and carbonized before activation. The carbonized tobacco has a low Brunauer-Emmett-Teller (BET) surface area of 111.25 m2·g−1, a pore volume of 0.11 cm3·g−1, an average pore diameter of 1.77 nm and a specific capacitance of 37 F·g−1 at a current density of 0.5 A·g−1. The TAC has a high BET surface area of 1297.6 m2·g−1, a large pore volume of 0.52 cm3·g−1, and a pore size distribution with a median pore size of 0.52 nm. It has a specific capacitance of 148 F·g−1 at a current density of 0.5 A·g−1 in a 6 M KOH electrolyte, and an excellent cycling stability with no capacitance fade after 9,000 cycles at a current density of 1 A·g−1.