Study On N-substituted Carboxyl Polyanilline Covalently Grafted Graphene And CdS Quantum Dots Photoelectric Materials

With the large consumption of fossil energy in the world and the irreversible effects on the environment,the development and utilization of new energy is imminent.Solar energy which as a clean,efficient and safe energy,becomes the focus of attention.And accompanied by the continuous improvement of photoelectric conversion technology,semiconductor photocatalyst,which has excellent catalytic effect can achieve the reasonable utilization of new energy and has good application prospects in the degradation of organic pollutants and hydrogen production under the solar light,attracted widespread attention of researchers.In this paper,a novel preparation method of N-substituted carboxyl polyaniline covalently grafted graphene/ CdS quantum dot photoelectric material,which possesses high photocatalytic efficiency and good cycle stability,was developed.The three-component materials in the composite are connected by covalent grafting,which not only shows good synergistic effect and interfacial force,but also suppress the defects of single component,thus improving the efficiency of photoelectric conversion under visible light.The specific research contents and related results are as follows:1.N-phenylglycine and cadmium acetate were introduced into solution to form cadmium containing precursors in an in-situ polymerization system which using anline-functionalized reductive graphene as the matrix,and then the composite was prepared by the nucleation between cadmiumwith sulfur.And a variety of CdS and CdS composites were prepared by different methods.The structure,size,stability and morphology of the different materials were characterized by FT-IR,UV-vis,XRD,XPS,TEM,TG,Raman and fluorescence.The results showed that CdS quantum dots were successfully connected with graphene and N-substituted carboxyl polyaniline by the covalent grafting method.Due to the introduction of conductive graphene and the protection of CdS quantum dots by N-substituted carboxylic polyaniline.the defects of CdS,which is easily agglomerated and photogenerated electron holes easily recombinated,were well suppressed.2.Electrodes modified with different CdS composites were prepared by drop coating method,and the electrochemical properties of the modified electrodes were characterized by cyclic voltammetry and electrochemical impedance spectroscopy.Firstly the effect of RGO/NPAN-CdS modifier dosage,scanning speed,pH on the activity of the modified electrode was optimized under light and dark conditions;Then the conductivity of the different modifie delectrodes was obtained by comparing the CV and EIS patterns;Fianlly,the stability of RGO/ NPAN-CdS modified electrode was detected by cyclic scanning.the electrochemicaldetections show that CdS quantum dots have excellent ability of photoelectric conversion and enhance photocurrent under visible light.and because of the introduction of graphene and NPAN,RGO/NPAN-CdS has shorter interfacial distance and faster electron transfer rate which let it has the highest electrical activity and minimum resistance in different CdS composites,and its stability with the recycling use is still remains good,so it can be applied to the preparation of practical electrochemical sensor.3.Photocatalytic degradation of RhB and photocatalytic H2 production with pure CdS and different CdS composites as photocatalysts under 500 W xenon lamp irradiation.First of all,the pH and temperature of RGO/NPAN-CdS were optimized to obtain optimum operating conditions;then comparing the capcities of photocatalytic degradation of RhB and photocatalytic H2 production with different CdS-based photocatalysts to get the best catalytic effect;Finally,the recycling properties of CdS-based photocatalyst were explored,and the stability of the material?s structure before and after photocatalytic was characterized by TEM and XRD.The study can be found: RGO/NPAN-CdS in the photocatalytic reaction showed the highest catalytic efficiency and reaction rate,the efficiency of degrading RhB and the amount of H2 production were 2.4 times and 8.6 times higher than that of pure CdS.And with the increase of use,compared to the structure of CdS is corroded and the catalytic efficiency is decreased,the efficiency and the structure of RGO/NPAN-CdS are still remain excellent,which proves that RGO/NPAN-CdS has potential application in photocatalysts.