Abstract

The world is transitioning to more ecologically friendly and renewable energy sources, and hydrogen has enormous prospects for consumption in the future (2050). An electrochemical water-splitting (WS) is the most effective approach for separating pure hydrogen (H2) from water, however, the production rate depends on the catalyst activity. Recent strategies are focused on modifying the morphological structure, altering the metal edges, and increasing the active sites of catalysts to enhance their electrochemical performance. Herein, the solvothermal structural modification methods employed to achieve the 3D nanoflowers CoS2-MoS2@NGA, the cost-effective metal catalyst were grown on a graphene aerogel (GA) surface. The electrochemical accomplishments of the as-prepared catalyst were examined in the alkaline and acid medium to determine the optimal electrolyte. The CoS2-MoS2@NGA composite material achieved a noticeably low overpotential of 38 mV at a current density of 10 mA/cm2 and the fastest Tafel slope of 63 mV/dec towards the hydrogen evolution reaction (HER) compared to pure CoS2, MoS2, and N-doped GA (NGA). The composite exhibits an extraordinary specific surface area of 53.6 m2/g and an electrochemical active surface area (EASA) of 24.77 mF/cm2, contributing to its stability over 2000 CV cycles without significant activity loss. Overall, the composite materials achieved a comparatively high surface, low overpotentials, faster kinetics, a highly active electrochemical surface, and excellent long-term robustness. This work presents a promising approach for the elegant structural modification of non-noble metals, positioning CoS2-MoS2@NGA 3D flowers as an extremely efficient electrocatalyst for HER in an acidic medium. © 2024 Elsevier B.V.