Research On The Field-assisted Preparation Of Black Phosphorene And The Application Of Electrocatalytic Ammonia Synthesis

Black phosphorus is a kind of direct bandgap semiconductor material with high carrier mobility and switching ratio.Black phosphorus has good application prospects in many energy and environment related fields such as catalysis and energy storage.The exfoliating of bulk black phosphorus into monolayer or multilayer phosphorene is an effective means to further control phosphorene physical and chemical properties.However,at present,most of the exfoliation methods of phosphorene are inefficient and complex,and the structure and sheet size of the obtained phosphorene are uncontrollable,which hinders the further application of phosphorene.In this paper,the efficient preparation method and application of phosphorene were studied.The method of preparation of phosphorene was developed by using sonication,microwave and electrochemical exfoliation to promote the exfoliation of phosphorene.On this basis,The phosphorene is used as an efficient catalyst for electroreduction of nitrogen.The research contents are as follows:?1?Herein,we propose an aqueous phase exfoliation method to greatly enhance the exfoliation efficiency and to lower the exfoliation time to less than two hours.In the end,the characterizations of the black phosphorus before and after exfoliation were carried out using Raman spectroscopy,scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,Atomic force microscopy?AFM?and UV-Vis absorption spectrum.The results show that the synergistic effect between sonication intercalation and microwave exfoliation is the key to promote the exfoliate of black phosphorus in aqueous phase.The phosphorene exfoliated by our method can be dispersed in water stably until 159 hours.?2?Phosphorene was successfully prepared from black phosphorus by a simple,fast,low-cost and controllable electrochemical exfoliation method.The optimum exfoliation conditions for the preparation of phosphorene by electrochemical exfoliation were determined by studying the electrolyte,concentration,voltage and temperature,and holey phosphorene was successfully prepared in ice-water bath.The results show that the layers number of holey phosphorene is only 1-2 layers,and the surface of the holey phosphorene has abundant porous structure,which can be used as an efficient catalyst for electroreduction of nitrogen.?3?Holey phosphorene can be used as a catalyst for electroreduction of nitrogen.In this paper,the holey phosphorene as catalyst,carbon cloth as carrier,0.01 M hydrochloric acid as electrolyte,and ammonia synthesis by electrocatalysis using water and nitrogen at room temperature and pressure.The results show that holey phosphorene is an environmentally friendly and efficient non-metallic catalyst.It has excellent electrical and optical properties,as well as anisotropic lattice structure.It has a good application prospect in the field of electrocatalytic ammonia synthesis.The valence electron structure of holey phosphorene is very similar to that of nitrogen,so holey phosphorene have higher nitrogen activation ability.The major advantage of holey phosphorene lies in its high specific surface area and abundant active sites,which make it have outstanding catalytic activity with high yield is 46.04 ugh^-1mg^-1cat and the Faraday efficiency is 10.33%.After five cycles of electrocatalytic tests,the holey phosphorene still maintained excellent electrocatalytic performance.