Interface engineering heterostructured MoS2/WS2-reduced graphene Oxide for enhanced hydrogen Evolution electrocatalysts

[Display omitted] •A new preparation, it is first time to fabricate WS2/MoS2-rGO hybrid.•The DFT calculations reveal that the synergistic effect can improve the HER efficiency.•The WS2/MoS2-rGO presents a low overpotential of 118 mV and a Tafel slope of 59 mV·dec-1.•The WS2/MoS2-rGO shows excellent cycle stability. Hydrogen Evolution Reaction (HER) has been regarded as a potential way to produce hydrogen with zero pollution emission. However, this route of HER still remains some difficulties due to the intrinsic sluggish kinetics, which requires a high efficient electrocatalyst to reduce the dynamic overpotentials. In our study, nanoflower-liked MoS2/WS2-reduced Graphene Oxide (rGO) heterostructures are rationally designed in experiments via a simple and easy-controlled two-step hydrothermal route. Attribute to the heterostructured MoS2/WS2-rGO with large special surface area, abundant active sites and the synergetic effect, the electrocatalytic activity of MoS2/WS2-rGO have markedly enhanced, only require a low overpotential (118 mV) to attain a current density of 10 mA cm−2 and the Tafel slope in response is 59 mV·dec-1. In addition, the first-principles calculations of density functional theory (DFT) revealed that the introduction of the interface actually couples MoS2 and WS2 by van der Waals (vdW) interaction and the synergistic effect can change the charge distribution, and thus enabling to improve the HER efficiency. A successful strategy to rational develop of electrocatalysts is attained by integration of experiment and theory, which might offer an avenue for the development of other heterostructured materials as electrocatalysis for water splitting.