Preparation Of Black Phosphorus And Its Application In Fiber Laser And Supercapacitor

Two-dimensional black phosphorus（BP）is a kind of layered material with its moderate and tunable bandgap,has become the focus of 2D material research.Single-layer and few-layer BP are predicted to bridge the bandgap range from 0.3 to 2 eV.Two-dimensional black phosphorus has captured researchers’interest in the application of optoelectronic devices because of his unique characteristic,such as superior saturable absorption characteristics,ultra-high carrier mobility,extremely high mechanical flexibility,thermodynamic stability and high biocompatibility extensive attention.As a new two-dimensional material,BP can be widely used in the fabrication of optoelectronic devices,such as field effect transistors,gas sensors,supercapacitors,and fiber lasers.In order to promote the industrial production of BP and the preparation of devices,the preparation of BP is also the focus of current research.In this paper has been studied:the preparation of BP,the preparation of BP nanosheets,the preparation of Polypyrrole（PPy）/BP films,and the performance of them in optoelectronic devices were also studied.The main research contents are as follows:1.Using commercial red phosphorus as raw material,BP is prepared by high-energy ball milling,which not only reduces cost but also is easy to operate.The structure of the preparation of BP was characterized by X-ray diffraction（XRD）,raman spectroscopy（Raman）,scanning electron microscopy（SEM）and so on.The experimental results show that the preparation method is simple,non-toxic and has a high repetition rate,which provides a new experimental scheme for the preparation of BP in large yield,and promotes the commercialization process and industrialization of black phosphorus.In addition,our experimental results demonstrated that the as-prepared black phosphorus could be used as a saturated absorber in a passive mode-locked fiber laser.The as prepared saturated absorber achieved a mode-locked pulsed laser output with a center wavelength of 1557.4 nm,a pulse width of 889 fs,and a repetition rate of 8.79 MHz.The BP nanosheets were prepared by liquid phase exfoliation.The prepared BP nanosheets was characterized by raman,transmission electron microscopy（TEM）and atomic force microscopy（AFM）to obtain a thickness is about 4-5 nm layer two-dimensional BP nanosheets.The PPy/BP flexible film was prepared by electrochemical deposition method.It was characterized by XRD,Fourier transform（FTIR）,TEM and SEM.PPy chain coated BP nanosheets to form a special layered structure.The film has excellent mechanical strength and flexibility,leading to a high capacity value of 497.5F g^-1(551.7 F cm^-3)and almost perfect capacitance retention after 10 000 cycles of charge and discharge.In a further study,we prepared this PPy/BP laminated film as electrode in an all-solid flexible supercapacitor.The as-prepared flexible device outstanding electrochemical performance and excellent mechanical flexibility.What’s more,the device achieved a high gravimetric capacitance of 452.8 F g^-1,corresponding to a volumetric capacitance of 7.7 F cm^-3 at a current density is 0.5 A g^-1.Experimental studies have shown that the high-performance flexible supercapacitors based on our PPy/BP film would be a promising energy storage device for a variety of portable electronics,stimulating other innovative combinations of conductive polymers and 2D materials with enhanced capacitance and cycle life.