Activated inert basal planes of Co@WS2/Co@MoS2 nanoflower to redistribute surface charge for electrocatalytic hydrogen evolution

Activating inert basal planes of transition metal composites through interfacial engineering and electronic modulation shows great potential on electrocatalytic hydrogen evolution reaction (HER). However, rational design of heterojunction structures through interfacial doping engineering still remains a costly and complicated challenge. Foreign atom doping can change the local electronic structure of the catalyst and adjust its catalytic performance. In this paper, the HER catalytic performance of WS2/MoS2 heterostructure is strongly boosted for the first time by double-layer Co doping, which could not only induces the formation of Co@WS2/Co@MoS2 hybrid interface but also regulates its d-band state. Additionally, activating the inert basal planes of the transition metal complex provides excellent electrocatalytic HER activity. Under the guidance of density functional theory (DFT) theory, a series of cobalt doped WS2/MoS2-based catalysts were systematically synthesized using a hydrothermal method. The prepared Co@WS2/Co@MoS2 catalyst exhibited remarkable electrochemical activity and durability in alkaline environment, with an extra-low overpotential of 117 mV for HER to deliver a current density of 10 mA·cm−2. The experimental results clearly prove the prediction of DFT simulations. This work provides new insights of interface structure construction for high-performance hydrogen evolution catalysts by adjusting the electron distribution.