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, 4WS(2)-96MoS(2) can cause the complete degradation of methylene blue within 150 min, and the difference value of the photocurrent can reach a value of 26 mu A, 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.