| Conductive polymer,as a kind of polymer material with good conductivity and adjustability,has a wide range of applications,and then the polymer material has poor mechanical properties,poor stability and other characteristics,so it has many defects when used alone.Therefore,in this paper,RGO-Fe3O4-PPy polymer nanocomposites are prepared,which provide a variety of source materials and adjustable surface functions,and cover up the defects of polymer materials when they were used alone.Compared with other materials,they have many advantages.In this paper,graphene oxide,ferric chloride,pyrrole and other materials were used as the main reactant raw materials.Firstly,the nanocomposites are prepared in situ in go suspension by chemical coprecipitation method,and then the RGO-Fe3O4-PPy nanocomposites are prepared by CTAB template method,and the corresponding characterization research is carried out to evaluate the performance of the materials.According to the experimental process,the following results have been achieved:Fe3O4 nanoparticles were prepared on the surface of graphene oxide by in-situ polymerization.It can be seen from SEM that Fe3O4 nanoparticles are evenly dispersed on the surface of graphene without obvious agglomeration,and the particle size of Fe3O4 is small,about 100 nm;a layer of polypyrrole was coated on the surface of RGO-Fe3O4 nanocomposites by CTAB template method.The yield of the composite was the highest when the ratio of pyrrole to oxidant was 0.4:1,the reaction temperature was 5℃,and the reaction time was 8 hours.The yield of the composite was 40.8%.Through XRD and FTIR analysis and XRD,it is proved that the preparation of polypyrrole is successful and effective,and from XRD,it reflects that polypyrrole is amorphous;from SEM,it can be seen that after the coating of polypyrrole,the surface of the composite becomes rough,and the formation of Fe3O4 nanoparticles can not be seen,which proves that the coating of polypyrrole is successful;from TEM projection electron microscope,it can be seen that The surface of Fe3O4 particles was coated with polypyrrole,which proved that the preparation of RGO-Fe3O4-PPy nanocomposites was successful.TGA and DSC were used to analyze the thermal stability of RGO-Fe3O4 and RGO-Fe3O4-PPy nanocomposites.In TGA analysis,the thermal weight loss of RGO-Fe3O4-PPy at the initial stage was less than that of RGO-Fe3O4,indicating that the composite of polypyrrole was conducive to improving the thermal stability of the materials.DSC showed that the glass transition temperature Tg of RGO-Fe3O4-PPy was 83.2℃,which was higher than that of RGO-Fe3O4,which was 75.6℃,It has been proved that the interface coordination between polypyrrole and RGO-Fe3O4 improves the thermal stability of RGO-Fe3O4-PPy nanocomposites.In order to study the electrical properties of RGO-Fe3O4-PPy,the preparation conditions of the optimal electrical properties were selected through the conductivity test.Through the experimental analysis,the polymerization temperature,the concentration of pyrrole monomer,the concentration of oxidant and the polymerization time all have a certain influence on the final conductivity of RGO-Fe3O4-PPy.The best scheme of conductivity is determined as follows:the polymerization temperature is 0℃,the concentration of pyrrole monomer is 0.15 mol/L,the concentration of oxidant is 0.3 mol/L,and the polymerization time is 8 h.At this time,the conductivity is 6 S/cm.In order to study the magnetic properties,VSM was used to measure the superparamagnetism.By measuring the magnetization,we can see that RGO-Fe3O4 and RGO-Fe3O4-PPy have superparamagnetism.The saturation magnetization of RGO-Fe3O4 is 40 emu/g.cyclic voltammetry(CV)was used for electrochemical analysis,under the same sweep speed,the integral area of the composition of RGO-Fe3O4-PPy is obviously larger than that of the intermediate product,and RGO-Fe3O4-PPy has better energy storage performance;at the same scanning speed,the energy storage performance of RGO-Fe3O4-PPy was studied.At the lower scanning speed of 5 mV/s,the best energy storage performance of RGO-Fe3O4-PPy was achieved,the specific capacitance was 385.3 F/g.EIS AC impedance test proved that RGO-Fe3O4-PPy had better conductivity.The kinetic adsorption process of RGO-Fe3O4-PPy and RGO-Fe3O4 was studied by using the kinetic theoretical equation and the empirical kinetic equation model.The experimental results were fitted.Among them,the linear correlation order of RGO-Fe3O4-PPy fitting is:quasi second-order dynamic equation>elovich equation>double constant dynamic equation>quasi first-order dynamic equation;the linear correlation order of RGO-Fe3O4-PPy dynamic fitting is:quasi second-order dynamic equation>double constant dynamic equation>elovich equation>quasi first-order dynamic equation.The second-order dynamic equation>elovich equation>double constant dynamic equation>first-order dynamics;the linear correlation order of RGO-Fe3O4-PPy dynamic fitting is:second-order dynamic equation>double constant dynamic equation>elovich equation>first-order dynamic equation.The results show that the adsorption process of RGO-Fe3O4 and RGO-Fe3O4-PPy for methyl orange solution is not a simple surface adsorption,but the results of the interaction of multiple adsorption methods meet the quasi second-order kinetic equation,so chemical adsorption is the most important part of the adsorption process.The adsorption isotherms of RGO-Fe3O4-PPy and RGO-Fe3O4 were studied by Langmuir and Freundlich isotherms.When using Langmuir Freundlich model equation for fitting,the linear correlation coefficient is greater than that of Freundlich Langmuir adsorption isotherm,so the whole process of adsorption of methyl orange solution by nanocomposites can be described by Freundlich Langmuir isotherm adsorption model equation.The maximum adsorption capacity of RGO-Fe3O4-PPy was 25.13 mg/g,while the maximum adsorption capacity of RGO-Fe3O4 was 16.61 mg/g,and the adsorption process of RGO-Fe3O4 and RGO-Fe3O4-PPy on methyl orange was mainly on the top of single molecular layer.In conclusion,the composite of conductive polypyrrole,Fe3O4,and graphene are beneficial to enhance the thermal properties,magnetic properties,adsorption properties and electrochemical energy storage properties of nanocomposites.It has potential application value as a new adsorption material and conductive adsorbent of battery. |
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