WS2 Films for Catalysis Application

Due to its unique band gap properties, inherent vacancy defects, and low electrical conductivity, WS₂ films can be used for catalysis. Catalysis including photocatalysis and electrocatalysis is essential in our daily life, and they have been widely used for environmental protection and clean energy generation.

The intrinsic properties of the material, such as morphology, crystal structure and specific surface area, determine the photocatalytic efficiency of the material. At the nanoscale, the higher specific surface area provides more active centers, facilitating the charge transfer of light-generated electron-hole pairs. The band gap and semiconducting properties of WS₂ are excellent for photocatalysis. In particular, the exfoliated WS₂ nanosheets with a band gap of 1.9 eV and a broad absorption spectrum in visible light showed good performance in several photocatalytic reactions, including the degradation of dyes and rhodamine B, the production of H₂, and the reduction of nitrophenols.

However, the catalysis activity of pure WS₂ films is very weak due to the rapid recombination of excitons, which hinders surface charge transfer. Therefore, researchers tried to improve the catalytic activity of WS₂ by compounding WS₂ with other substances. xu et al. used a modified liquid exfoliation method to prepare monolayer and bilayer semiconductor WS₂ nanosheets. They mixed WS₂ and CdS in different mass ratios to form WS₂/CdS hybrids.

Subsequently, in the photocatalytic hydrogen production with lactic acid as a sacrificial electron donor, the H₂ release rate of the WS₂/CdS hybrid system was 26 times higher compared to pure CdS, and the optimal photocatalytic quantum yield was greater than 60%. three-dimensional composites of graphene oxide/WS₂ nanosheets/Mg-doped ZnO nanohybrids (rGOWMZ) were prepared by Chen et al.

(Photo source: Rosanna Mastria et al/Nature)

They optimized the interfacial charge transfer of rGOWMZ, a three-dimensional composite with the effective synergy of the components leading to enhanced photocatalytic activity.

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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