Convenient Synthesis of WS₂-MoS₂ Heterostructures with Enhanced Photocatalytic Performance

A series of WS₂-MoS₂ composites with different phase ratios have been successfully constructed. First, WS₂ with hexagonal phase structure has been achieved by directly annealing a mixture of commercial W and S powders in an Ar atmosphere. Then the hydrothermal method is utilized to realize the epitaxial growth of MoS₂ onto the surface of WS₂. The dual-petal nanostructure of WS₂-MoS₂ composites has been revealed by scanning electron microscopy and transmission electron microscopy. The measurement of the optoelectronic property illustrates that WS₂-MoS₂ heterostructures can present more active sites and a higher effective separation of carriers than can bare WS₂ and MoS₂. Specifically speaking, 4WS₂-96MoS₂ can cause the complete degradation of methylene blue within 150 min, and the difference value of the photocurrent can reach a value of 26 μA, which obviously outperforms that of bare MoS₂ and WS₂. These aforementioned improved performances are closely related to this rationally designed structure for WS₂-MoS₂ heterostructures and are expected to be promising applications in the field of optoelectronic devices.