Study On The Electrocatalysis And Electroanalysis Performance Of Electrophoretically Deposited Pt,Pd And Au Nanoparticles

Noble metal nanomaterials have attracted much attention in the fields of energy,biotechnology,and analytical detection due to their high chemical stability,high catalytic activity,and good biocompatibility.How to reduce the use cost of noble metal materials and improve their utilization has always been an important research topic.In this thesis,on the basis of a brief review on platinum nanoparticles（Pt NPs）,palladium nanoparticles（Pd NPs）and gold nanoparticles（Au NPs）and their preparation methods,electrophoretic deposition（EPD）techniques,and carbon nanomaterials,new methods for EPD of Pt NPs,Pd NPs or Au NPs were developed,and the performance of electrocatalytic hydrogen evolution reaction and drug electroanalysis on thus-prepared modified electrodes were examined.The main contents are as follows.1.Pt NPs/3DHPNG/Au_pla/GCE was prepared by pulse-plating of gold on a glassy carbon electrode（GCE）,dynamic hydrogen bubbles templete（DHBT）electrodeposition of three-dimensional honeycomb-like porous nanogold（3DHPNG）,and then the EPD of Pt NPs in an aqueous mixture of Na Cl O₄ and a Pt NPs dispersion.The EPD processes and mechanism of Pt NPs are explained by the electrooxidation of the remaining Na BH₄ and its oxidation intermediates to produce H⁺to neutralize the surface charges of Pt NPs.Compared with a Pt modified electrode obtained by the conventional electroreduction of H₂Pt Cl₆,the electrophoretically deposited Pt NPs can be more uniformly distributed and have the larger specific surface area and the better electrocatalytic effect.The performance of electrocatalytic HER in 0.5 M aqueous H₂SO₄ was investigated.Under optimized conditions,the linear sweep voltammetry test on Pt NPs/3DHPNG/Au_pla/GCE in 0.5 M aqueous H₂SO₄ showed that the overpotential at-10 m A cm^-2 current density was only 10.0 m V（vs RHE）and the Tafel slope was 25.2 m V dec^-1,which are better than those of most Pt-based electrocatalysts reported so far.2.On a carboxylated multiwalled carbon nanotubes（C-MWCNTs）modified GCE（C-MWCNTs/GCE）,Pd NPs were electrophoretically deposited by the electrooxidation of coexisting L-sodium ascorbate（L-C₆H₇O₆Na）to produce H⁺that can neutralize the negative charges on the Pd NPs,yielding a Pd NPs modified C-MWCNTs/GCE（Pd NPs/C-MWCNTs/GCE）.Under optimized conditions,the（Pd NPs/C-MWCNTs/GCE）showed a sensitivity of 1.63μA/μM and a LOD（S/N=3）of 30 n M for the electroanalysis of cefepime in 0.04 M B-R buffer（p H 4.5）.3.On an electroreduced carboxylated graphene（er CG）modified GCE（er CG/GCE）,Au NPs were electrophoretically deposited by the electrooxidation of coexisting H₂O₂ to produce H⁺that can neutralize the negative charges on the Au NPs,yielding an Au NPs modified er CG/GCE(Au NPs _EPD/er CG/GCE).Under optimized conditions,the Au NPs _EPD/er CG/GCE showed sensitivity values of 0.299μA/μM and0.890μA/μM as well as LOD values（S/N=3）of 0.41μM and 0.43μM,for the simultaneous electroanalysis of ascorbic acid（AA）and acetaminophen（AC）in 0.1 M phosphate buffer solution（PBS,p H 6.0）,respectively.