Study On Preparation Of Arsenene Nanosheets By Liquid Phase Exfoliation And Doping Regulation Of Arsenene Nanosheets

Due to the potential toxicity of arsenic,traditional arsenic related products are gradually banned.The excellent properties of new arsenic materials provide a new direction for the application.In several new arsenic materials,arsenene nanosheets were predicted to be an excellent semiconductor materials because of their wider band gap and the super-large carrier mobility.However,the applications of arsenene nanosheets were limited by their low preparation efficiency,large thickness and few band gap.In order to solve these problems,arsenene nanosheets and Bi/Te doped arsenene nanosheets were successfully prepared by liquid phase exfoliation and chemical vapor transport in this study.First,the influencing factors of exfoliation were analyzed.Then,the exfoliation efficiency of arsenene nanosheets between different assistant were evaluated and the assistant exfoliation mechanism was explained.Finally,the effects of arsenene nanosheets band gap between different doped elements were analyzed.These studies provide new ideas for efficient preparation and doping regulation of arsenene nanosheets.The main results are summarized as follows:(1)Arsenene nanosheets with different morphologies,sizes and thicknesses could be obtained by controlling the ultrasonic time,solvent and centrifugal speed in ultrasonic liquid phase exfoliation.The factors of arsenene nanosheets exfoliation efficiency were analyzed by Raman,TEM,DLS and UV-vis.(2)Assistant were used to improve the exfoliation efficiency of arsenene nanosheets.The exfoliation efficiency of nanosheets between different assistant was analyzed by Raman,TEM,DLS,UV-vis,XRD and FTIR.Then,the preparation efficiency of arsenene nanosheets after assistant in different solvent were compared.Further,the assistant exfoliation mechanism was explained.The results showed that using polyvinylpyrrolidone(PVP)as the exfoliation assistant,the yield of arsenene nanosheets can be increased to 37.08%,and the thickness can be reduced to 3.5 nm.PVP forms a complex with the arsenic.The repulsion between arsenene nanosheets is caused by the long chain of PVP penetrates into the solvent.Then,the dispersibility of arsenene nanosheets improved in solvent and the enhancement of exfoliation efficiency realized.(3)Bi/Te doped arsenene precursors and nanosheets can be prepared by combining the chemical vapor transport and the ultrasonic liquid-phase exfoliation.The factors in precursors preparation and the preparation effect of doped arsenene nanosheets were analyzed by XRD、SEM、TEM and XPS.Besides,the band gap of different doped arsenene nanosheets was compared.The results showed that the band gap is 1.96 eV-2.28 eV in Bi doped arsenene nanosheets and the band gap gradually decreases with the improvement of Bi concentration.However,for Te doped arsenene nanosheets,the band gap is 1.88 eV-2.17 eV and the band gap gradually increases with the improvement of Te concentration.