Preparation And Applications Of Graphene-based Composites For Supercapacitors And Electrical Analysis

Graphene materials are widely used because of their physical and chemical properties such as large specific surface area and good electrical conductivity.However,due to its inevitable agglomeration effect,there are obvious shortcomings in the field of supercapacitor and electrical analysis.In order to give full play to the excellent properties of graphene materials,functional groups were introduced to functionalize graphene.This paper first summarized for supercapacitor and electrochemical sensor,on the basis of graphite oxide reduction in addition to the graphene,introduced in graphene metal oxides and quinone material preparation of the graphene modified material,assemble the excellent performance of super capacitor,and implements the detection of hydroquinone and catechol.The main contents are as follows:1.Phosphomolybdate/graphene columnary material?HPMB/GR?was prepared by one-step hydrothermal method and characterized by SEM,TEM,thermogravimetric method,N₂ adsorption/desorption method and XPS method.The results showed that molybdate entry effectively reduced the agglomeration of graphene and increased the specific surface area of the composites.In 0.5 mol L^-1H₂SO₄ electrolyte solution,the mass ratio capacitance of HPMB/GR composite electrode is up to 395 F g^-1(current density is 1 A g^-1),and shows excellent stability.The working voltage of the reciprocal supercapacitor assembled with HPMB/GR composite material is 1.2 v,and its energy density is as high as 31.2 Wh kg^-1at a power density of 600 W kg^-1.2.Graphene/molybdenum trioxide?GR/MoO₃?was prepared by one-step Hydrothermal method and characterized by XRD,SEM and N₂adsorption/desorption.The results show that in the three-electrode system,when the current density is 0.5 A g^-1,the specific capacitance of GR/MoO₃ composite material is as high as 440 F g^-1,which is much higher than that of MoO₃(235 F g^-1).The composite material modified with glassy carbon electrode was used for the detection of hydroquinone.Under the best conditions,the detection range was 5?M?800?M,and the detection limit was 2.0?M.3.The neutral red/graphene?NR/GR?composite material was obtained by the adsorption of neutral red by graphene,and the material was characterized by TEM,SEM,FT-IR and elemental analyzer.The results show that when the current density is 1 A g^-1,the mass ratio capacitance of NR/GR composite material is up to 497 F g^-1,and shows excellent cyclic stability.NR/GR composite material is used as the electrode material of the supercapacitor to assemble symmetrical supercapacitor.The working voltage is 1 V,and the energy density can reach 16.25 Kh kg^-11 when the power density is 0.25 Kw kg^-1.The composite material modified with glassy carbon electrode was used for the detection of catechol.Under the best conditions,the detection range was 50?M?1500?M and the detection limit was 15?M.The results were satisfactory.