The Fabrication, Analysis And Application Of Platinium, Gold And Cu₂O Nanomaterials

It is human urgent choice to increasing energy using ratio and using regenerativesource instead of fossil energy. Fuel cells has been become a hot research point for hishigh ratio of energy conversion, little pollution and kind for surroundings. The solarfuels and hydrogen production by photolysis have a research point too. Great progresshas been made in the study and application of DMFCs in the world. However thecatalysts of DMFCs are still the hinder for commercial of DMFCs because of Pt ofhigh loading and poor activity. We use new methods to fabrication new catalyst forDMFCs.1.Platinum nanoparticles were successfully electrodeposited on indium tin oxide(ITO) surface in the solution with hexachloroplatinic acid and copper ion by cyclicvoltammogram method. The micrographs and structure of Pt nanoparticles werecharacterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD),respectively. The electrocatalytic properties of Pt nanoparticles/ITO or modified byRu, Bi underpotential deposition (UPD) for methanol oxidation have beeninvestigated by cyclic voltammetry (CV) and chronoamperometry (CA). Highelectroactivity and good long-term stability can be observed. These results indicatethat Pt nanoparticles modified by UPD may have potential applications in designingnoble metal catalysts of fuel cells with low loading and high activity at the atomiclevel2. With polystyrene latex spheres self-assembled on ITO glass as templates, highlyordered twodimensional(2D) Pt nanoparticles (PtNPs) were prepared byelectrochemical deposition. Themorphology and element composition of PtNPs werecharacterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) andX-ray photoelectron spectroscopy (XPS). The electrocatalyticproperties of PtNPs/ITOand Sn underpotential deposition (UPD) modified PtNPs/ITO for methanoloxidationhas been investigated by cyclic voltammetry (CV) and chronoamperometry (CA). Theexcellentelectrocatalytic activity can be observed for these catalytic systems. 3. With polystyrene latex spheres self-assembled on ITO glass as templates,highly ordered macro-porous Pt was prepared by electrochemical deposition. Then themacro-porous Pt was modified by Pd monolayer involving the galvanic displacementof Cu monolayer formed by under-potential deposition on macro-porous Pt. Thecorresponding results showed that Pd-modified macro-porous Pt electrode hadnegative catalytic for methanol oxidation in compared with macro-porous Pt. ButPd-modified macro-porous Pt electrode had positive electro-catalytic activity to O₂reduction.4. A simple one step process for preparation of nanoporous Au materials has beendevelopment of sacrificial templates of Ag nanowires in a mixture solution of HAuCl₄at 100℃. The morphology and crystal structure of the product were characterized byscanning electron microscopy (SEM), XPS and XRD. The results indicated that thenano-porous gold had generally preserved the original orientation of Ag nanowires.The Au nanoporous materials consist of nanotubes, giving them a porous nature. Sucharrays of well oriented gold nano-materials are expected to show interestinganisotropic optical and electronic properties, and their hollow porous structures mightfind broad potential applications in catalysis and chemical sensing.5. Cuprous oxide nanoparticles were prepared by using hydrothermal methods andwere characterized by XRD, and TEM methods. The electrochemical properties ofnano-Cu₂O were studied. The experimental results indicate that nano-Cu₂O showshigh signal of photo-electricity. The photo-catalytic activity of the nanostructures wasevaluated by examine the degradation of methylene blue and fungicide carbendazim.