Tungsten Disulfide for Electrocatalysis Application

Tungsten disulfide (WS2) is promising electrocatalysis with a layered structure with adjustable electrical properties and exposed edges that can act as the active center. It is mainly used as an electrocatalyst for hydrogen evolution reactions. The surface of WS2 is inert; however, the catalytic activity of WS2 occurs at the lamellar edges, which determines the overall catalytic performance. In order to improve the catalytic effect of WS2, the electrolyte must be in complete contact with the WS2 layer.

(Photo source: Rosanna Mastria et al/Nature)

The researchers proposed two effective strategies: (a) increasing the active surface area by exposing the edges to the electrolyte; and (b) increasing the intrinsic activity of each active site. The active centers of electrocatalysis are mainly concentrated at the edges of the2 H-MS2 crystal layer. To obtain WS2 structures with more active centers, researchers are currently investigating defect engineering, phase transformation, and nanostructuring. Yin et al. synthesized oxygen-rich hybrid WS2 with edge defects by adjusting the concentration of reactants.

The main principle is to enhance the catalytic activity of WS2 by doping oxygen atoms to form surface defects. Recently, composite catalysts have started to show higher electrocatalytic performance than single-component catalysts due to the synergistic effect of various components. Many studies have shown that WS2 can be combined with certain nanomaterials to prepare composite catalysts, thus controlling the overgrowth of nanomaterials and preventing the occurrence of self-aggregation.

Chen et al successfully prepared highly efficient CoP/WS2 nanosheet composites for hydrogen evolution electrocatalysts. In the CoP/WS2 nanosheet composites, the WS2 nanosheets with abundant active sites successfully supported the CoP nanoparticles with good dispersion. This heterogeneous structure resulted in an optimal synergy between CoP nanoparticles and WS2 nanosheets. The CoP/WS2 nanosheet composites showed excellent hydrogen evolution performance compared to when CoP and WS2 were used alone.

(Photo source: Rosanna Mastria et al/Nature)

Cited Article: Ding J, Feng A, Li X, et al. Properties, preparation, and application of tungsten disulfide: A review[J]. Journal of Physics D: Applied Physics, 2021, 54(17): 173002.

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