Cleanly synthesizing rotten potato-based activated carbon for supercapacitor by self-catalytic activation

A novel self-catalytic activation approach is developed for the preparation of hierarchically porous carbon from rotten potato wastes. Metals already existing within the rotten potatoes were used as the catalysts and gases emitted during pyrolysis were used as the activating reagents, leading to the cleaner production of hierarchically porous carbon materials without additional reagents. The as-made activated carbon exhibits high BET surface area of 2201 m 2  g −1 , optimal hierarchically porous, and good conductivity of 14.2 S cm −1 . When fabricated into a symmetrical supercapacitor , it displays a relatively high capacitance of 54 F g −1 (29.2 F cm −3 ) at 0.5 A g −1 , and excellent cycling reliability of exceeding 100% retention after 5000 cycles in 6M KOH, and an energy density of 20.8 Wh kg −1 (11.2 Wh L −1 ) in 1 M TEABF 4 /AN. More importantly, the approach outlined herein also offers a promising strategy for cleaner production of advanced activated carbon derived from other biomass wastes.