ZIF-8 derived porous carbon material with improved specific surface area for supercapacitor application

Abstract

In the present study, the effects of Acetylene gas in single-stage carbonization on the pore structures and supercapacitor performances of Zeolitic Imidazolate Framework (ZIF-8) derived porous carbons were investigated. The analysis demonstrated that when hydrocarbon gas was flowing, the final ZIF-derived products had a more appropriate degree of graphitization due to modifications in the carbonation kinetics. Moreover, the enhancement of specific surface area indicated that the incorporation of acetylene gas into the carbonization atmosphere could possibly prevent structural collapse. The promotion of the mesoporous structure increased surface area from 846 m².g⁻¹ for the reference sample to 1720 m².g⁻¹ for ZIF-derived samples were exposed to 20 sccm of acetylene (ZAC-20). To examine the capacitive performance, all ZIF-derived carbons were employed as the electrode material. The results demonstrate that the ZAC-20 sample attained a capacitance of 292.6 F.g⁻¹ at an applied current density of 0.25 A.g⁻¹. This value represents an enhancement of approximately 63 % in comparison with the carbonized sample that was not exposed to acetylene. Furthermore, an assembled symmetrical supercapacitor comprising ZAC-20 as both electrodes demonstrates energy densities of 10.62 and 3.59 W.h.kg⁻¹ at power densities of 162.6 and 13,000 W.kg⁻¹, respectively.