Dissolution-assistant all-in-one synthesis of N and S dual-doped porous carbon for high-performance supercapacitors

The rational design and synthesis of porous carbons as supercapacitor electrodes have received tremendous attentions. In this study, a facile all-in-one pyrolysis strategy was developed for producing N and S co-doped porous carbon (NSC), by utilizing cellulose, the most abundant natural reproducible carbohydrate, as precursors. A binary aqueous solution consisting of 9.5% NaOH and 4.5% thiourea served as solvent, porogen and doping reagent, simultaneously. The dissolution and lyophilization procedures allowed a homogeneous mixture, thus achieving a superb activation and doping effects after the pyrolysis. The resultant NSC demonstrated a highly-developed porous texture with a specific surface area of 1588 m2 g−1 and appropriate heteroatom functionalities with N and S contents of 3.82% and 1.94%, respectively. For three-electrode system, NSC had a high specific capacitance of 288 F g−1 at 0.5 A g−1 in 6 M KOH electrolyte, which was comparable to or even better than many reported cellulose and cellulose derivatives based porous carbon electrodes. The as-assembled NSC//NSC symmetrical cell displayed excellent rate capability and durability, depicting a hopeful candidate for supercapacitors.