Electrochemically Exfoliated Black Phosphorus Nanosheets And Quantum Dots By Choosing Different Solution Concentration

Black phosphorus is a new type two-dimensional material.More and more scientists pay attention to it.Now an electromechanical exfoliated method which uses intercalation reaction to exfoliate black phosphorus will be introduced.By choosing different solution concentration,different nanostructure like nanosheets and quantum dots could be produced.Through controlling a single variable,black phosphorus nanosheets or quantum dots could be obtained,the different nanostructure both have big production and excellent quality.Among them nanosheets and quantum dots both could be applied in electronic and medical treatment applications.So the work presents an excellent method to produce nanoscale black phosphorus which could be used in factory producing.The electrical voltage,solvent and solute is the same in all experiments.Different solubility is prepared to control a single variable to get different nanostructure.The solvent is organic to prevent black phosphorus react with water or air.According to surface tension not all solvent is efficient to exfoliate black phosphorus.To improve intercalation reaction efficiency,a suitable solute must be found too.After lots of experiments we choose DMF(dimethyl formamide)as solvent and lithium chloride as solute.The match has an outstanding end.Black phosphorus is used as anode and platinum as cathode.A platinum clamp is used to fix a patch of black phosphorus which prevent impurity be introduced.7 V voltage is applied for 30 minutes to soak the black phosphorus and then it was improved to 10 V.The voltage would sustain until the reaction end.The exfoliate will last 30 minutes to 1 hour as the change of solubility.The solubility will control the exfoliated nanostructure.In 0.1 M solution we only get bulk black phosphorus.The 0.3 M solution will exfoliate excellent black phosphorus nanosheets.Black phosphorus quantum dots and nano sheets complex substance will appear in 0.5 M solution.However only black phosphorus quantum dots would be observed in 1 M solution.The mechanism of the exfoliation of nanosheets and quantum dots could be understood as different solubility of free radicals will cause the dominance change of normal force,sheer force and fragmentation these three common forces in liquid phase exfoliated experiments.And then the different leading force will exfoliate different product.Among these nano-product,we only focus on quantum dots to research its application.Photothermal cancer therapy and humidity sensor is the main research aspect.Finally,the result is excellent.