Hollow-tubular porous carbon derived from cotton with high productivity for enhanced performance supercapacitor

Hollow-tubular porous carbon is synthesized from NaH2PO4 layer coating natural biomass cotton fiber through a facile carbonization and KOH-KNO3 activation process. It shows that the obtained porous carbon keeps the initial fiber structure of hollow-tubular, resulting in a high surface area of 1508 m(2) g(-1) and obvious mesoporous structure (9.18 nm). With coating of NaH2PO4 layer, high productivity (27.3%) of the obtained carbon can be achieved which is two times higher than the untreated cotton. The obtained porous carbon exhibits high specific capacitance (278 F g(-1) at 1 A g(-1)) and excellent rate capability (208 F g(-1) at 100 A g-1), showing the much higher rate performance than that of other biomass-derived carbon materials. Moreover, the carbon also displays a superior-short charge-discharge time (1.89 sat 100 A g(-1)) and super long cycle life (94.3% retention over 10 x 10(4) cycles at 100 A g(-1)). This excellent electrochemical performance mainly belongs to its special hollow-tubular morphology and activated porous structure. Hence, this method is a new strategy for the porous carbon production as high-power supercapacitor material with larger product yield and special structures which are inherited from natural biomass.