High-pressure Synthesis Of Layered Phosphorus-based Materials And Their Property Research

In this thesis,two-dimensional?2D?phosphorus-based materials?black phosphorus,tellurium doped black phosphorus and GeP₅?are regared as the research object,and the preparation of large-scale black phosphorus?BP?and Te doped BP along with physical properties control of BP via Te were systematically expored.Besides we explored the regulatory mechanism of BP storage performance via CNT,achieved the oriented growth of the large-scale GeP₅ and exported its novel energy storage performance.The specific research is carried out from the following four aspects:?1?Based on high temperature and high pressure technology?HTHP?and special heating furnace structure,the synthesis of large scale and high quality BP was successfully achieved,which provided a rich material foundation for the following research on few layers BP.In addition,the excellent electrical transport performance of bulk and few layers BP were studied.With the extension of air exposure time,the surface morphology and elemental change process of BP nanoflake were directly analyzed by using atomic force microscope and X-ray photoelectron energy spectrum technology.?2?For the bottleneck problem of poor environmental stability of few-layer BP,we prepared Te doped BP by HTHP.A series of field-effect transistors?FETs?based on mechanically exfoliated Te doped BP were prepared and conducted the environment of atmospheric exposure test research,which showed that doping with Te boosted transport performances and ambient stability of BP devices.Combined with the first-principles calculations,we have established the mechanism of retaining black phosphorus degradation by the Te doping.A new experimental method and theoretical interpretation were proposed to solve the problem of poor environmental stability of two dimensional BP crystals.?3?As a super capacitor electrode material,BP nonoflakes have shown excellent electrochemical energy storage performance,while it is restricted due to its preparation technology and poor conductivity.We prepared the smooth BP nanosheet and carbon nanotube?CNT?composite film by vacuum filtration technology,and found that when the mass ratio of BP nanosheet and CNT in the composite film was 1:4,the composite electrode device showed excellent electrochemical energy storage performance,as well as excellent mechanical flexibility,high cycle stability and environmental stability.We have opened up new possibilities for the application of BP in energy storage devices.?4?The 2D materials with high electrical conductivity have more excellent electrochemical energy storage performance.In generally,2D GeP₅ crystal with high conductivity was synthesized by mechanical milling,which results in bad crystalline crystalline quality.Using HTHP technology,we synthesized large scale and high quality2D GeP₅ crystals,whose conductivity at room temperature could reach 2.24×10⁶ S m^-1.The GeP₅ ASSPs have exhibited excellent electrochemical properties,along with outstanding mechanical flexibility and superior cycling stability.In addition,GeP₅ ASSP demonstrated an outstanding frequency response performance,indicating a high AC line-filtering efficacy.These properties indicate that the metallic GeP₅ ASSP is an excellent electrochemical capacitor that can work under kHz.