(434 m 2 g -1 ), and CNT@PDA (389 m 2 g -1 ). The lower SBET of CNT@CZIF composites are attributed to the denser property of polydopamine than CNTs, which could lead to the increase in diameter and finally decrease the SBET. The supercapacitive performances of the prepared materials were analysed in a three-electrode cell using 6 M KOH electrolyte. At 0.5 A g -1 , the specific capacitance of CNT@CZIF-2 (324 F g -1 ) was higher than that of CNT (78 F g -1 ), CNT@PDA (136 F g -1 ), and CNTWCZIF-1 (168 F g -1 ), respectively. The CNT@CZIF-2 electrode showed the capacitance retention of 93.5% after 1000 charge-discharge cycles. The better supercapacitive performances of CNT/CZIF-2 are attributed to the largest amount of pyridinic nitrogen and graphitic carbon as active sites, and the long-standing stability could be probably due to the balanced SBET, high N content, and the adequate ratio between highly conductive support and active sites under a pyrolysis temperature of 800 ˚C.