Research On Preparation And Optoelectronic Properties Of Zinc Oxide-graphene Composite

Graphene is a regular hexagonal network structure connected by a single layer of carbon atoms in the form of sp2 hybrid.Because of its unique two-dimensional structure,graphene has excellent physical and chemical properties,such as good transmittance,excellent conductivity,high tensile strength and thermal conductivity.In recent years,composites based on graphene have many advantages and potential applications.As a direct band gap band gap semiconductor material,zinc oxide has the advantages of simple preparation,low cost,good chemical stability and so on.It is widely used in the fields of luminescence,photocatalysis,light detector,light emitting device and solar cell.The fast recombination of photogenerated electron hole pairs in zinc oxide limits its performance.Graphene has higher specific surface and conductivity,which helps to improve the properties of zinc oxide.Therefore,it is of great significance to study zinc oxide-graphene composite materials.In this paper,the modified Hummers method was used to prepare graphite oxide,and then zinc oxide-graphene composite was prepared by hydrothermal method and water bath heating method.The chemical composition,structure and morphology of products were characterized and analyzed by XRD,SEM,TEM,Raman,XPS,FTIR,etc.The results show that the graphite oxide prepared by the improved Hummers method has high oxidation degree.In zinc oxide-graphene composites,graphite oxide was reduced to graphene.The quasi core shell structure of zinc oxide encapsulated by graphene has been recognized with the help of TEM.Then,the zinc-graphene composite materials were used to photocatalytic degradation of dye methyl orange(MO)and rhodamine B(Rh B).The photocatalytic results showed that the composite had better photocatalytic activity than zinc oxide.Graphene has a high specific surface so that it is easier to adsorb dye molecules.Besides graphene has excellent electronic transmission properties,which is beneficial to the separation and migration of photogenerated electron hole pair and contributes to the enhancement of photocatalytic performance.In addition,as graphene is a zero band gap material,the composite can absorb the visible light band compared with zinc oxide,which can improve the utilization of solar energy and improve the photocatalytic performance.Finally,the zinc oxide-graphene composite is prepared into a UV detector,and the performance of the device is tested by the electrochemical workstation.The test results show that the UV detector using the zinc oxide-graphene composite is a photoconductive detector.The photo response rate and responsivity of detectors have been improved compared with UV detectors based on zinc.The UV detector based on zinc oxidegraphene composite material has a rise time of 5.5 s and a decrease of 13.4 s.