Organic Modification Of Reduced Graphene Oxide(RGO) And Research On Composite Material Of RGO And Metal Organic Framework(MOF)

Graphene is a two-dimensional material with a single atomic layer thickness,which has excellent electronic,optical,thermal and mechanical properties and has a large specific surface area.Because of these advantages,graphene is used in electrochemistry,catalysis,transparent conductive films,supercapacitors,field effect transistors,metal ion batteries,solar cells,hydrogen storage media,biosensors,composite materials and other fields.Based on the excellent electrical conductivity of graphene,we first prepared a high-conductivity graphene material,and did two works:covalent organic modification was carried out on the edge of graphene,the modified graphene material can be used as the basic material for manufacturing sensors,combining graphene material with metal organic framework(MOF)and using it for catalytic reduction of CO2.Among the various preparation methods of graphene,we chose the oxidation-reduction method,which can not only retain some functional groups on graphene but also obtain higher conductivity.We adopt the improved Hummers method without using sodium nitrate,using potassium permanganate to graphite powder mass ratio of 9:1 as the raw material,concentrated sulfuric acid as the solvent to prepare graphene oxide(GO)more safely and efficiently to avoid a large amount of damage to graphite during high-temperature oxidation In-plane conjugate structure.Hydroiodic acid method,hydroiodic acid ethanol method,and hydroiodic acid acetic acid method were used to prepare reduced graphene oxide(rGO),it was found that the hydroiodic acid acetic acid reduction method is a mild and efficient reduction strategy.A certain amount of acetic acid in a mixed solution of 55%hydroiodic acid,graphene oxide powder was reduced at 40? for 1 d,electrical conductivity of product reached 14 600 S/m,which was higher than the other two systems.Through improved oxidation-reduction conditions,graphene was prepared,oxygen-containing functional groups only remain at the edges of rGO but there is almost no damage to the in-plane conjugated structure.When performing edge modification on the preparation product rGO,it was found that rGO was well dispersed in o-dichlorobenzene by ultrasound,then,bromine-containing modifier 4-(2-bromoethoxy)-aniline and isoamyl nitrite was used as the raw material,the edge organic modification of rGO was carried out by the diazotization reaction,bromine atoms which could be used as reaction sites were introduced.In the preparation of rGO and MOF composite materials,ZrCl4,4,4'-stilbene dicarboxylic acid(H2L)and rGO are used as raw materials,the rGO and MOF composites are prepared in one step by the solvothermal method,the product named rGO/Zr-MOF.The solid ultraviolet test and transient photocurrent test of the composite found the possibility of current generation.The photocatalytic reduction experiment and comparative experiment of CO2 were carried out.It was found that the composite can achieve the reduction of CO2 compared with pure MOF,Is the result of light absorption performance and excellent electrical conductivity of graphene and catalytic performance of MOF.