Study On The Catalytic Degradation And Sensing Of Small Molecules Based On Graphene Noble Metal Nanocomposites

With people's attention to environmental pollution and biomedicine,the catalytic degradation of small molecular compounds,such as p-nitrophenol,has been deeply studied in recent years.Graphene noble metal nanomaterials are effective assembly of graphene and noble metal nanoparticles.Noble metal nanoparticles provide efficient catalytic sites and graphene provides reaction sites.The synergistic effect of graphene and noble metal nanoparticles makes the composite materials have excellent catalytic degradation for environmental pollutants such as nitrophenol,and can also be used as catalytic sensing materials for electrochemical sensors.In order to speed up the degradation efficiency of graphene noble metal nanomaterials in catalyzing p-nitrophenol,overcome the shortcomings of stacking of two-dimensional graphene sheets,inadequate exposure of active sites,and poor material transfer,it is necessary to adopt specific technologies to compose graphene noble metal nanomaterials.In this paper,graphene microspheres were prepared by spray drying method and graphene films were prepared by CVD method.The catalytic degradation of p-nitrophenol and the electrochemical detection of hydrogen peroxide by gold nanoparticles and platinum nanoparticles were studied.The main contents of this paper are as follows:(1)The graphene microsphere composite was prepared by spray drying,and the gold nanoparticles were loaded inside the graphene microspheres.The three-dimensional microspheres formed by spray drying could effectively inhibit the self-stacking of graphene,while the three-dimensional graphene structure could effectively disperse gold nanoparticles and avoid the self-aggregation of gold nanoparticles.The nanocomposites of rutile and graphene microspheres have been applied to the degradation of p-nitrophenol,showing excellent catalytic performance and stability.(2)We successfully grew graphene on quartz glass after etching pretreatment by chemical vapor deposition(CVD),and found that the etching pretreatment of quartz glass can effectively shorten the growth time of graphene on quartz glass.Then,the platinum nanoparticles were sputtered and fixed in the quartz glass graphene by the magnetron sputtering technology.The nano platinum/quartz glass graphene composite can be used as a transparent electrode to assemble into an electrochemical sensor,which can realize the electrochemical detection of hydrogen peroxide(H2O2).The sensor had a rapid reaction(less than 2 s),and the minimum detection limit was as low as 3.3 nM.