Exploring the electrocatalytic properties of binder-free RGO/MoS2 heterostructure for hydrogen evolution reaction

Herein, MoS2 and RGO/MoS2 heterostructure catalysts synthesized using the solvothermal scheme are used for electrocatalytic hydrogen generation in green energy applications. Further, SEM images confirm that both MoS2 and RGO/MoS2 heterostructure catalysts demonstrate hierarchical shapes, which promote the formation of new active sites on the catalyst surface, which improves electrocatalytic activities. Fascinatingly, the RGO/MoS2 heterostructure catalyst portrays an overpotential of 122 mV at -10 mA cm- 2 current density and 132 mV dec-1 Tafel slope of hydrogen evolution. However, RGO/MoS2 heterostructure catalyst depicts a low series and charge transfer resistances of 0.71 S2, and 2.4 S2 deduced from the EIS plot. The integration of RGO with MoS2 enhances the electrical conductivity, modifies the surface chemistry, and synergistic effects, facilitating fast electron transfer, which stimulates the formation of active sites on the RGO/MoS2 heterostructure catalyst surface that leads to enhanced electrocatalytic hydrogen generation. Besides, the RGO/MoS2 heterostructure catalyst reveals excellent stability for 20 h at -10 mA cm- 2 for HER using chronopotentiometry, demonstrating excellent potential retention with minimal variation, indicating its suitability for long-term hydrogen evolution application. Also, it systematically explores the catalytic reaction mechanism in the alkaline electrolyte medium, revealing the path of the reaction mechanism and the role of the RGO/MoS2 heterostructure interface. The findings demonstrate the high activity and stability of the RGO/MoS2 heterostructure as a promising catalyst for hydrogen production in sustainable energy applications.