Preparation of GO-based Cr-Zn bimetallic layered porous sulfide by ZIF template method for high performance supercapacitors

Abstract

In this work, rGO/Cr2ZnS4 composites was composited with reduced GO using ZIF-8 as the template. Firstly, GO/ZIF-8 was obtained by in-situ synthesis strategy, and then ZIF-8 was etched by chromium nitrate to obtain CrZn-LDH. Finally, rGO/Cr2ZnS4 was successfully synthesized after calcination and sulfuration. Due to the synergistic effect between Cr2ZnS4 and rGO, the hybrid electrode has significantly improved energy storage capacity in terms of the high specific capacitance of 958.6 F g−1 at 1 A g−1 and good cycling stability after 10,000 cycles (63.1 % of the initial value under 10 A g−1) in a three-electrode system. Meanwhile, the asymmetric supercapacitor was prepared using rGO/Cr2ZnS4 composite as the positive electrode and AC (active carbon) as the negative electrode. The fabricated asymmetric supercapacitor has high energy density of 47.7 Wh kg−1 at power density of 749.54 W kg−1 and capacity retention of 50 % after 5000 cycles. This work offers a promising approach for designing advanced hybrid materials of transition metal sulfides for high energy density supercapacitors.