Synthesis And Property Of Graphene Oxide And Ferrite Nanocomposites

With the development of modern technology science, absorbing-wave materialbecame the hot point in the military field of stealth technology. The research ofabsorbing material is mainly focused on abosrobing-wave nanopowder and doping orcomposite. In this thesis, ferrites were compounded with graphene oxide to improvetheir electromagnetic properties. The main research content is as follows:First of all, graphene oxide was prepared with graphite powder which was oxidizedby strong oxidant and then treated at high temperature as raw material. It wascharacterized with XRD, SEM and IR spectrum. The results showed that grapheneoxide was honeycomb and plicated in the edge and that oxygen group was introduced tothe graphene oxide. The effect of processing papameters on structure and morphologyof graphene oxide was studied and the best parameters were obtained:3g KMnO4,2hlow temperature and high temperature of95℃.Secondly, using cobalt nitrate, nitric acid iron, zinc nitrate and graphene oxide asraw material, sodium hydroxide as precipitating agent, the oxidation graphene/cobaltzinc ferrite composite was successfully prepared by hydrothermal method. Theinfluence of technological factors on the sturture and morphology of the composite wasinvestigated in detail: cobalt zinc ferrite and oxide graphene was1:1, temperature was180℃, time was13h, pH was9. SEM results showed that nanoparticles were uniformlyloaded on the graphene oxide sheet layer treated by hydrothermal method., XRDanalysis indicated the presence of cobalt zinc ferrite and oxidation graphenecharacteristic peak. IR spectrum analysis explained that double bond of carbon andcarbon of graphene oxide opened and that C-Fe-O bonds formed in the reaction process.The magnetic property analysis showed that with the increasing of the ratio, saturationmagnetization and coercive force decreased due to low crystallization of ferrite patticles.Finally, graphene/nickel zinc ferrite composite was prepared by sol-gel methodwith the citric acid as chelating agent. The optimum process parameters were obtainedby the discussion to the influence factors: nickel zinc ferrite and oxide graphene was1:0.75, mixing time was2+2h, pH was5, sintered atmosphere was weak oxygen, sinteredtime was2h, sintered temperature630℃. The composite was characterized with XRD,SEM, IR spectra and magnetic properties. The results showed that graphene oxide andnickel zinc ferrite composite was prepared by sol-gel method successfuliy and that itsmagnetic properties was comparatively good. The structure, morphology and magneticproperties of graphene oxide/nickel zinc ferrite composite prepared by hydrothermalmethod and sol-gel method respectively was contrasted.