Synthesis of γ-MnS/nanoporous carbon/reduced graphene oxide composites for high-performance supercapacitor

In the present work, nanoporous carbon (NPC) was prepared from a metal–organic framework (zeolite imidazolate framework 8, ZIF-8). Different concentrations of graphene oxide (GO) were used to make NPC/reduced graphene oxide (NPC/rGO-x, x = 0.5, 1.0, 1.5, and 2.0) composites, and then γ-MnS/NPC/rGO-1 composite was synthesized via a simple hydrothermal technique. The electrochemical characteristics of porous carbon composites (NPC/rGO-x) and γ-MnS/NPC/rGO-1 electrodes were investigated by galvanostatic charge and discharge, cyclic voltammetry, and electrochemical impedance spectroscopy. NPC/rGO-1 showed the highest specific capacitance of 207 F/g at 0.5 A/g. Also, the γ-MnS/NPC/rGO-1 electrode demonstrates exceptional electrochemical performance with a high specific capacitance of 300 F/g at 0.5 A/g and impressive cyclic stability of 70% capacitance retention after 10,000 cycles at 1 A/g. As a result, this study demonstrates that γ-MnS/NPC/rGO-1 electrode can be considered a promising candidate for high-performance supercapacitors.