Preparation Of Bimetallic Nanoparticles Supported On Functionalized Doped Graphene And The Electrochemical Application

Graphene(GR)is two-dimensional nanomaterial consisting of a single layer of sp~2network of carbon atoms.It is an ideal material for electrochemistry because of its very high conductivity,large surface area and low cost.However,graphene is hydrophobic and has poor dispersion in the solution,which limits its further application.Notability,heteroatom-doped graphene is apractical way to effectively modify its structures,electrical properties and facilitate their applications.In this dissertation,basised on the characteristics of heteroatom-doped graphene,we focused on the functionalized heteroatom-doped graphene to improved its dispersibility and electrocatalytic activity.Then the bimetallic nanoparticles anchored on the surface of functionalized heteroatom-doped graphene,and the nanocomposite used to electrochemical application research.The main contents are described as follows:1.Au-Pt bimetallic nanoparticles supported on functionalized nitrogen-doped graphene for sensitive detection of nitriteIn this work,we report a novel Au-Pt bimetallic nanoparticles(Au-PtNPs)decorated on the surface of nitrogen-doped graphene(NG)functionalized with 1,3,6,8-pyrene tetra sulfonic acid sodium salt(PyTS)by direct electrodeposition method.The results of scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS)and electrochemical impendence spectrum(EIS)reveal that the Au-PtNPs were successfully anchored on the surface of NG sheets with a diameter of20-40 nm.Further,the prepared Au-PtNPs/PyTS-NG nanocomposite exhibits superior catalytic activity for the oxidation of nitrite.Under optimal experimental conditions,an amperometric sensor with a linear range of 0.5-1621?M and a detection limit of0.19?M(S/N=3)for the detection of nitrite was set up and applied to real samples.2.Pd-Pt bimetallic nanoparticles anchored on functionalized nitrogen and sulfur co-doped graphene as an excellent electrocatalysts for methanol oxidationIn this work,a novel catalyst,Pd-Pt bimetallic nanoparticles(Pd-PtNPs)supported on the surface of sulfonic groups functionalized nitrogen and sulfur co-doped graphene(S-N,S-GR)was successfully synthesized by chemical reduction method using ethylene glycol as a soft reductant.The results of scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),and X-raydiffraction(XRD)reveal that the Pd-PtNPs were successfully anchored on the surface of N,S-GR sheets with a diameter of 20-40 nm.Meanwhile,electrochemical experiments,including cyclic voltammetry and chronoamperometric measurements,were performed to investigate the electrochemical and electrocatalytic properties of the Pd-PtNPs/S-N,S-GR electrocatalysts.Compared with PdNPs/S-N,S-GR,PtNPs/S-N,S-GR,and Pd-PtNPs/N,S-GR electrocatalysts,the prepared Pd-PtNPs/S-N,S-GR displays better electrocatalytic ability and stability for methanol oxidation in alkaline media,which is attributed to the synergistic effects of Pd,Pt,and N,S-GR.Futher,as new anode catalyst materials,the Pd-PtNPs/S-N,S-GR could be used for direct methanol fuel cells.