Efficient hydrogen evolution and high energy density solid state supercapacitors using rGO/MoS2 heterostructure electrodes

Abstract

Hydrogen generation and supercapacitors can provide solutions to meet global energy demand. Here, we demonstrate the 2H-MoS2 nanosheets and rGO-MoS2 heterostructure as active materials for hydrogen evolution and supercapacitors. In acidic medium, rGO-MoS2 heterostructure shows better catalytic activity for HER with overpotential ∼ 190 mV and Tafel slope ∼ 52 mV dec−1 compared to overpotential ∼ 199 mV and Tafel slope ∼ 59 mV dec−1 for MoS2 nanosheets. Similarly, rGO-MoS2 based solid state supercapacitor device with PVA-H2SO4 gel electrolyte shows higher specific capacitance of ∼ 90 F g−1 and energy density of ∼ 24.5 Wh kg−1 compared to ∼ 72 F g−1 and ∼ 19.6 W h kg−1 for MoS2 based SSC device, respectively. The better performance of heterostructure could be due to higher active sites and faster kinetics at its surface. © 2023 Elsevier B.V.