Monomer self-deposition synthesis of N-doped mesoporous carbon tubes using halloysite as template for supercapacitors

Abstract

N-doped mesoporous carbon tubes (NMCT) can be widely used as electrode materials in supercapacitors with high performance due to their length-diameter ration, low tortuosity, openness, high specific surface area, large pore volume and electrical conductivity. Herein, a universal monomer self-deposition method is developed to prepare NMCT, which was the self-deposition of 3-aminophenol (3-AP) on natural halloysite nanotubes (HNTs) acted as template assisted by strong adsorption effect due to HNTs porous structure and catalytic action of surface acidity of the HNTs. The as-prepared NMCT possessed completely reproduced the morphology of HNTs, showing hollow tubular structure, thin shell, large specific surface area of 1071 m2 g−1, uniform mesoporous distribution and high nitrogen content of 4.04 at%. The pyrolysis temperature and mass ratio of 3-AP to HNTs show strongly influence on the specific surface area and pore volume of as-prepared NMCT, leading to the discrepancy in electrochemical performances for supercapacitor. Under optimal conditions, benefiting from the distinctive structural feature and desirable N doping, the NMCT exhibits a high specific capacitance of 269 F g−1 at 0.5 A g−1 and an excellent rate capacitance retention of 92.3% after 10,000 stability cycles, demonstrating its great potential in the application of supercapacitors.