Preparation And Photoelectric Properties Of MoS₂ Nanoscrolls

Two-dimensional（2D）transition metal dihalides（TMD）have attracted considerable attention in recent years due to their outstanding physical and chemical properties,such as high mobility,tunable band structure,van der Waals interface,excellent field-controlled electrical properties and good mechanical flexibility.As the most widely studied representative material of TMDs,molybdenum disulfide（MoS₂）has shown many excellent properties and wide applications in the fields of optoelectronics,energy conversion/storage and catalysis.The self-sealing of 2D MoS₂ into quasi-one-dimensional nanosrolls still inherits a series of advantages of 2D materials,and even has more prominent performance in some aspects.The mobility and photosensitivity of internal carriers（electrons or holes）of MoS₂ nanoscrolls are significantly improved compared with 2D MoS₂,and the environmental stability is greatly enhanced,which shows the great potential of MoS₂nanoscrolls in the field of photoelectric detection.However,the research on MoS₂nanoscrolls is still in its infancy.The study on its photoelectric properties can fill many gaps in this field,and is of great significance to basic scientific research.In this paper,based on the existing research,the preparation of MoS₂ nanoscrolls,the measurement and optimization of photoelectric properties are mainly explored.The main research work is as follows:MoS₂ nanosrolls were prepared by solution assisted rolling,and the effect of ethanol solution concentration on the formation of nanosrolls was investigated.When the volume ratio of ethanol to deionized water is 1:3,the concentration of ethanol solution drives the rolling most easily and the rolling process is more even and controllable.The photodetector based on MoS₂ nanoscroll has a slight decrease in optical responsiveness,external quantum efficiency and specific detection ratio compared with MoS₂ nanosheet.This may be related to the fact that the curvature of the lattice opens new electron scattering channels and that the transverse size of the nanocreels is too large,resulting in the photoelectric gain of the tight scroll structure is not obvious.MoS₂ nanosheets and nanoscrolls have good periodic light cycling,but the noise effect in nanoscroll devices is more obvious.At the same time,MoS₂ nanoscrolls have a faster response than nanosheets.The open topology of the internal structure of MoS₂ nanoscrolls provides a tremendous operable space for optimizing their optoelectronic properties.In this paper,zero-dimensional barium titanate（Ba Ti O₃）nanoparticles were combined with 1D MoS₂ nanoscrolls to form0D/1D heterostructure（Ba Ti O₃/MoS₂ nanoscrolls）to control the photoelectric properties of molybdenum disulfide nanocoils.Compared with single-layer MoS₂ nanoscrolls,the photoelectric properties of MoS₂-Ba Ti O₃ nanoscrolls are significantly improved at low incident light power（470nm@0.584m W/cm²）,the photoresponsiveness R increased by 64times to 73.9 A/W,and external quantum efficiency EQE increased by 66 times to 1.95×10⁴%.The 0D/1D hybridization provides a useful way to compensate the performance decline of 1D van der Waals materials associated with the the curvature of the lattice,hence,vital for those one-dimensional optoelectronic devices.