Convenient Synthesis of WS₂–MoS₂ Heterostructures with Enhanced Photocatalytic Performance

Abstract

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.