Mechanism Research Of Two-dimensional 1T-TaS₂ Controllable Preparation And Exploration Of Related Device Performance

Since the discovery of graphene,its optical,electrical,mechanical properties,excellent performance in materials science,micro-nano processing,new energy,biomedicine,and drug delivery have received a lot of research attention.The zero band gap characteristic of graphene has limited its application in certain fields.Therefore,a series of transition metal disulfides(TMD)with two-dimensional structures have been designed and developed to control the band gap,electrical conductivity,and elongation.Various characteristics such as sex and phase state.Among these two-dimensional materials,1T-TaS₂ has received extremely high research attention because of its rich phase change structure and variable temperature superconductivity.However,the large-scale preparation of 1T-TaS₂ two-dimensional materials is still one of the main reasons that hinder the progress of this material.As far as we know,the two-dimensional 1T-TaS₂ prepared by CVD method has problems such as low growth efficiency,small crystal area,and low quality.Long growth time and high-cost substrates also cause waste of resources.At the same time,the two-dimensional 1T-TaS₂ material has been widely used in hydrogen evolution catalytic devices,humidity sensors and other fields because of its low internal resistance and abundant active sites.However,the above-mentioned application devices based on two-dimensional 1T-TaS₂ have problems such as difficulty in large-scale preparation,low performance improvement,and in-depth exploration of the relationship between material morphology and performance.In response to the above problems,this article has launched a series of work and made some progress in the following three aspects:(1)We have developed a chemical vapor deposition(CVD)method based on the first use of ?(military confidential materials,replaced by ?)and ****(military confidential materials,replaced by *)as substrates and catalysts to assist extremely thin atoms 1T-TaS₂ growth method.This method can greatly increase the growth rate and crystalline area of 1T-TaS₂.At the same time,the layered 1T-TaS₂ structure obtained based on this method has application value in the field of hydrogen evolution catalytic devices,humidity sensors and other application devices.Use atomic force microscopy(AFM),ultra-high resolution field emission transmission electron microscopy(HRTEM),Raman spectroscopy,X-ray photoelectron spectroscopy(XPS)and other means to prove that the material has a good lattice structure.At the same time,a synthetic route for LPCVD single crystal nanowires was designed,and a thermogravimetric analyzer was used to verify the rationality of ****(military confidential material,replaced by *)to catalyze the growth of 1T-TaS₂.(2)Aiming at the hydrogen evolution catalytic performance of 1T-TaS₂,by studying the hydrogen evolution performance of three different morphologies of TaS₂(double-sided sheet,single-sided sheet single-sided film,double-sided film)with growth time,cycle times and other conditions,it is found that the double-sided The TaS₂ ultra-thin layer has high catalytic performance for hydrogen evolution.The hydrogen evolution catalytic device has an overpotential of-253 m V,and has good cycle stability(1000 cycles stable),and the substrate material is low in cost and easy to obtain,and it is expected to realize large-scale applications.Using LSV test,impedance test,Tafel curve test,cycle stability test and other methods,the reasons for the difference in the performance of hydrogen evolution catalytic devices with different structures and different growth times were explored.Finally,it is concluded that the difference in performance is attributed to the changes in the morphology of the material and the concentration of active sites.(3)Use the 1T-TaS₂ layered structure prepared by ?(military confidential material,replaced by ?)as the humidity sensitive material,and use the electric intercalation peeling method,ultrasonic intercalation and other means to process the1T-TaS₂ layered sample into various morphologies Specific structure or two-dimensional sheet structure,using optical microscope,SEM and other means to characterize the rules of these specific structures.Finally,find the rules and optimal conditions that modulate the performance of the humidity sensor with the changes of the material morphology and surface pores,etc.,to achieve the directional control of the performance of the humidity sensor,and obtain the adsorption and desorption times of 2 s and 40 s,respectively.The TaS₂ material with a value of 2.87×104 has the best humidity sensitivity.