MoS2 Nanoflowers Grown on Plasma-Induced W-Anchored Graphene for Efficient and Stable H-2 Production Through Seawater Electrolysis

Herein, it is found that 3D transition metal dichalcogenide (TMD)-MoS2 nanoflowers-grown on 2D tungsten oxide-anchored graphene nanosheets (MoS2@W-G) functions as a superior catalyst for the hydrogen evolution reaction (HER) under both acidic and alkaline conditions. The optimized weight ratio of MoS2@W-G (MoS2:W-G/1.5:1) in 0.5 M H2SO4 achieves a low overpotential of 78 mV at 10 mA cm(-2), a small Tafel slope of 48 mV dec(-1), and a high exchange current density (0.321 mA cm(-2)). Furthermore, the same MoS2@W-G composite exhibits stable HER performance when using real seawater, with Faradaic efficiencies of 96 and 94% in acidic and alkaline media, respectively. Density functional theory calculations based on the hybrid MoS2@W-Gstructure model confirm that suitable hybridization of 3D MoS2 and 2D W-G nanosheets can lower the hydrogen adsorption: Gibbs free energy (?G(H*)) from 1.89 eV for MoS2 to -0.13 eV for the MoS2@W-G composite. The excellent HER activity of the 3D/2D hybridized MoS2@W-G composite arises from abundance of active heterostructure interfaces, optimizing the electrical configuration, thereby accelerating the adsorption and dissociation of H2O. These findings suggest a new approach for the rational development of alternative 3D/2D TMD/graphene electrocatalysts for HER applications using seawater.