Graphene/noble Metal Composite Aerogel Materials Prepared By ?- Ray Radiation And The Research On Its Catalytic Performance

Graphene-based aerogel composite materials have great application prospects in the fields of energy and environment,especially in the fields of catalysis,adsorption,electrodes,capacitors and sensors due to their excellent and unique physical and chemical properties.Currently,graphene-based aerogel composites have been effectively prepared by kinds of traditional hydrothermal method,template-based method,chemical reduction method and so on.However,these methods usually are implemented with high temperature and high pressure,template or reducing agents addition,which have limited their actual application and large-scale production.It is urgent to develop more greener and convenient preparation method.In this dissertation we creatively fabricated the three-dimensional porous graphene based aerogels combined with noble metals with?-ray irradiation.Then the application of obtained graphene/noble metal composite aerogel materials in catalysis were studied.And the main research contents and analysis results were summarized as following:?1?Preparation of graphene/Pt composite aeroges and its application in catalytic degradation of methyl orange?MO?.In ethanol/water system and N₂ atmosphere,GO and[PtCl₆]^2-were simultaneously reduced by?-ray irradiation method and self-assembled into graphene/platinum?GH/Pt?composite porous hydrogel materials.The 3D graphene/platinum?GA/Pt?composite porous aerogels were obtained by freeze-drying.The platinum nanoparticles in the honeycomb-like network structure GA/Pt composite aerogel have a size range of 2-6nm.By using XPS?XRD?BET?TGA and other characterization techniques,we obtained the structural information on chemical structural changes,surface areas and thermal stability of GA/Pt composite aerogel materials.Due to synergistic catalysis between graphene and Pt NPs,GA/Pt composite aerogel materials catalyzed MO with excellent catalytic performance.Under the same catalytic conditions,its catalytic efficiency was 4 times that of pure Pt NPs.?2?Preparation of graphene/Ag composite aerogels and its application in catalytic reduction of 4-nitrophenol?4-NP?.Under the same conditions,this chapter successfully prepared graphene/silver composite porous aerogel?GA/Ag?.The silver nanoparticles in the porous network structure GA/Ag composite aerogel have a size range of 20-60 nm.XPS?XRD and TGA showed that C/O molar ratio of the GA/Ag composites were increased and the thermal stability were improved.Due to the synergistic catalysis between graphene and Ag nanoparticles,GA/Ag composites performed excellent catalytic performance and catalyzed the concentration of 4-NP up to 2.16×10^-3 mol/L,which was higher than other composites by chemical methods.?3?Preparation of graphene/Au composite aerogels and its application in catalytic reduction of 4-nitrophenol?4-NP?.In view of the preparation of the above graphene-based materials,we have successfully prepared graphene/gold?GA/Au?composite porous aerogel materials.Basic information such as porous microstructure,6-35 nm of particle size distribution,increased C/O molar ratio,improved thermal stability of GA/Au composite aerogel materials were obtained by SEM?TEM?XPS?XRD and TGA.On the basis of catalytic test results,we found that GA/Au composite aerogel materials have better catalytic performance for 4-NP than GA/Ag composite aerogel materials.Its catalytic concentration of 4-NP can reach 6.48×10^-3 mol/L,which is 3 times that of GA/Ag composite aerogel material.The above experimental results have provided deep insight into the fabrication of graphene/noble composite aerogel materials and adsorption-catalysis experiments.