Facile preparation of porous carbons derived from orange peel via basic copper carbonate activation for supercapacitors

Abstract A facile activation method has been illustrated for the synthesis of porous carbons derived from orange peels using basic copper carbonate as activation agent. The resulting carbon material possesses a high specific surface area of 912.4 m2 g−1, hierarchical pore architecture with interconnected meso-/macropores, and a rich amount of nitrogen, oxygen and sulfur heteroatoms. Benefiting from to its unique pore structure and the co-existence of redox-active nitrogen, oxygen and sulfur functionalities, the obtained porous carbon shows outstanding electrochemical performance when used as electrode material for supercapacitors. The as-prepared porous carbon exhibits a high specific capacitance of 375.7 F g−1 at 1 A g−1 and good rate retention of 50.9% from 1 to 100 A g−1. Additionally, the assembled carbon-based symmetric supercapacitor delivers a high energy density of 31.3 W h kg−1 at a power density of 499.5 W kg−1 in 1.0 M Na2SO4 electrolyte as well as superior long-term cyclic stability (only 7.3% of capacitance loss after 50,000 cycles within a voltage window of 0–2.0 V). This work provides an easy and feasible way for the synthesis of hierarchical porous carbon materials with both high power and energy density.