Preparation And Application Of Black Phosphorus Nanomaterials

In recent years,two-dimensional materials have been widely used in electronic devices,solar cells,biosensing and other fields due to their excellent properties.Such as large specific surface area and high carrier mobility,attracting the attention of many researchers.As an important member of the two-dimensional material family,black phosphorus has the characteristics of wrinkled layered structure,tunable band gap and biocompatibility,so it has great application prospects in the fields of catalysis,electronic devices and biomedicine.Because black phosphorus easily reacts with oxygen in the air,it reduces the crystallinity and uniformity of the material,thereby affecting its optical and electrical properties.Therefore,this paper focuses on the preparation of black phosphorus nanomaterials with high crystallinity and uniform size,and explores the preparation methods,degradation characteristics of black phosphorus nanosheets and quantum dots,and their applications in electrocatalysis and drug delivery:(1)In this study,N-Methylpyrrolidone(NMP)was used as a solvent to prepare black phosphorus nanosheets by ultrasonic liquid phase exfoliation.The effects of different exfoliation times on the size of black phosphorus nanosheets were studied respectively.Black phosphorus nanosheets of different sizes can be effectively separated.The obtained black phosphorus nanosheets were characterized by UV-Vis spectroscopy,TEM,XRD,Raman spectroscopy,XPS and other means,and found that they have excellent dispersion,size uniformity,and low oxidation.On this basis,a large number of atomic-level defects are etched on the surface of black phosphorus nanosheets by hydrothermal and solvothermal methods to realize the loading of cobalt atoms,thereby improving the surface utilization rate of black phosphorus nanosheets.Electrochemical tests show that the loadi ng of cobalt atoms effectively enhances the OER activity of black phosphorus nanosheets,and the overpotential decreases from 1200 m V to 348 m V.The results of XPS and XAFS showed that the formation of Co-P bonds between the loaded cobalt atoms and the black phosphorus carrier enhanced the charge transfer rate between the two,thereby promoting the OER activity of the black phosphorus nanosheets.(2)In this study,black phosphorus quantum dots were prepared by ice-bath-assisted ultrasonic liquid phase exfoliation using N-Methylpyrrolidone(NMP)as solvent.By means of TEM,Raman spectroscopy,AFM and other characterization methods,it was found that the ultrasonic time in ice bath was negatively related to the size of black phosphorus quantum dots.In vitro photodynamic(PDT)tests showed that black phosphorus quantum dots can induce the production of singlet oxygen,proving that they have certain PDT activity.On this basis,cisplatin(a chemotherapeutic drug)was successfully loaded on black phosphorus qua ntum dots by electrostatic interaction,which provided an experimental basis for the subsequent realization of PDT/chemotherapy dual-mode treatment of tumors in vivo.