Convenient Synthesis of WS₂–MoS₂ Heterostructures\nwith Enhanced Photocatalytic Performance

Abstract

A series\nof WS₂–MoS₂ composites with\ndifferent phase ratios have been successfully constructed. First,\nWS₂ with hexagonal phase structure has been achieved by\ndirectly annealing a mixture of commercial W and S powders in an Ar\natmosphere. Then the hydrothermal method is utilized to realize the\nepitaxial growth of MoS₂ onto the surface of WS₂. The dual-petal nanostructure of WS₂–MoS₂ composites has been revealed by scanning electron microscopy and\ntransmission electron microscopy. The measurement of the optoelectronic\nproperty illustrates that WS₂–MoS₂ heterostructures\ncan present more active sites and a higher effective separation of\ncarriers than can bare WS₂ and MoS₂. Specifically\nspeaking, 4WS₂–96MoS₂ can cause the complete\ndegradation of methylene blue within 150 min, and the difference value\nof the photocurrent can reach a value of 26 μA, which obviously\noutperforms that of bare MoS₂ and WS₂. These\naforementioned improved performances are closely related to this rationally\ndesigned structure for WS₂–MoS₂ heterostructures\nand are expected to be promising applications in the field of optoelectronic\ndevices.