ZIF-8 derived nitrogen-doped porous carbon/carbon nanotube composite for high-performance supercapacitor

Abstract Nitrogen-doped porous carbon/carbon nanotube composite was prepared by in situ growth of porous nitrogen-abundant ZIF-8 nanoparticles onto carbon nanotubes (CNT) and subsequent carbonization at 800 °C. With the aid of polydopamine coating, the distribution of ZIF-8 particles on CNTs could be controlled by varying the synthesis time of ZIF-8. Due to the synergy of high electrical conductivity of carbon nanotubes and abundant nitrogen active sites of ZIF-8-derived carbon, the as-prepared composite material (CNT@CZIF-2) with a BET surface area of 287 m 2  g −1 was tested as supercapacitor electrode, and it exhibited specific capacitance of 324 F g −1 and 93.5% of capacitance retention after 1000 cycles in an alkaline aqueous electrolyte solution. Such excellent energy storage performance was superior to that achieved by most of the reported CNT-based electrodes.