Notoginseng-derived B/N co-doped porous carbon with high N-doped content and good electrochemical performance

Biomass is regarded as the ideal carbon sources for the preparation of porous carbons owing to its abundance, environmental friendliness, and facile availability. Herein a novel biomass, notoginseng, is used as the carbon source for synthesizing a novel B/N co-doped porous carbon (BNC) via one-step carbonization/activation procedure with the presence of copper chloride and boric acid. It is found that utilization of copper chloride and boric acid to fulfill one-step activation not only promotes the fixation of heteroatom-containing species but also facilitates formation of abundant micropores and mesopores in the carbon matrix. The as-prepared BNC sample thus exhibits developed porosity, large specific surface area (982 m(2) g(-1)), and plentiful heteroatom dopants (e.g., N, 10.51 at.%; O, 15.38 at.%; B, 0.7 at.%). Investigation of supercapacitive performance reveals that the BNC electrode holds a delightful capacitance of 261 F g(-1) at 0.5 A g(-1) and a good rate capacitance of 172.8 F g(-1) at 10 A g(-1) in 6 M KOH electrolyte; and its symmetric supercapacitor exhibits excellent cyclic performance (capacitance retention, 93.2%) during 10,000 cycles at 5 A g(-1), and a moderate energy output of 6.16 W h kg(-1) at 100.12 W kg(-1). These findings indicate that the notoginseng-derived porous carbon is a promising electrode material for supercapacitors due to its simple preparation method and superior electrochemical performance.