Preparation Of Graphene Nanoscrollswith Heterostructure And Their Application

As a new type of fuel cell,direct methanol fuel cell(DMFC)has attracted people’s interest because of its low cost,rich sources of fuel,green and non-pollution.However,the platinum(Pt)catalyst is expensive and easy to loss and agglomerate,reducing its catalytic activity.CO can make the catalyst poisoned,decresing its catalytic activity as well.The design and preparation of new catalysts with high-efficiency and low-cost have become the emphasis of research.Graphene nanoscrolls,with the open ends,adjustable diameter and interlayer galleries,can be prepared by curling two-dimensional graphene sheets under freezing conditions.The unique structure of graphene nanoscrolls makes it have an extensive application in the field of catalysis.In this paper,the bimetallic metallic Pt-Ag catalyst or bimetallic MOF was loaded on the surface of graphene oxide(GO)which as the basic unit.Next,graphene nanoscrolls were prepared by lyophilization method and the electrocatalytic performance for methanol oxidation was also studied.The main contents of this paper are as follows:(1)Preparation of RGO-PDMAEMA-Pt/Ag nanoscrolls and its electrocatalytic performance for oxidation of methanolPDMAEMA chains with terminal pyrene groups were synthesized by atom transfer radical polymerization and were introduced to GO sheets via ?-? stacking interaction(GO-PDMAEMA sheets).The Pt/Ag alloy nanoparticles were uniformly loaded onto the surface of GO-PDMAEMA sheets by a co-reduction method while GO sheets were also reduced.Finally,the RGO-PDMAEMA-Pt/Ag nanoscrolls were prepared by lyophilization method.The structure and morphology of the product was characterized by Fourier transform infrared spectroscopy,scanning electron microscopy and Raman spectroscopy.The electrocatalytic oxidation of methanol was also studied.(2)Preparation of heterostructure RGO-Co-N-C nanoscrolls and its electrocatalytic performance for oxidation of methanolFirst,GO sheets were modified with diazonium salts of p-aminophenol sulfonic acid.Under room temperature,Co-Zn-MOF were prepared with 2-methylimidazole as ligand,cobalt nitrate hexahydrate and zinc nitrate hexahydrate as metal centers.Next,the Co-Zn-MOF particles were loaded on the surface of GO sheets and were curled underfreezing conditions.The curled-up structures graphene-MOF nano-composites were carbonized at 800 ℃ and RGO-Co-N-C nanoscrolls were obtained.The structure and morphology of the products were characterized by Fourier transform infrared spectroscopy,scanning electron microscopy and XRD.The electrocatalytic oxidation of methanol was also studied.