| In the research of biosensor and fuel cells, nanomaterials for electrocatalyst has been drawn a lot of attention due to their unique properties, such as volume effect, surface effect, quantum size effect, tunnel effect and dielectric confinement effect. These characteristics provide several special properties of nanomaterials in physical and chemical properties、 magnetic properties、optical properties、electrical properties and catalytic activity. Thus, the nanomaterials have large potential applications for microelectronic devices, microsensor and catalyst carrier, etal. What is important is the large surface area of nanomaterials. It can greatly increase the loading of metal nanoparticles and bio-enzymes or other catalysts on their surface, significantly. Science the electro-catalytic ability of oxidation for nano-catalyst has greatly enhanced that conducive to build a more efficient catalytic system. In this thesis, we have described a rapid and facile method for fabrication of Pt/reduced graphene oxide nanoscrolls (Pt/RGOS) and bio-molecular polymer modified carbon nanotubes electrocatalyst. The morphology, structures and properties of the obtained catalysts have been investigated by transmission electron microscope (TEM), scanning electron microscopy (SEM), the specific surface area of the tester (BET), energy dispersive X-ray spectroscopy (EDS), Raman spectroscopy (Raman), X-ray diffractometer (XRD). Electrochemical voltammetry and steady-state chronoamperometry methods were used to evaluate the electrochemical active surface area and electrocatalytic activity in methanol oxidation. The main contents in thiswork are listed in the following:(1) Pt/reduced graphene oxide nanoscrolls (Pt/RGOS) electrocatalyst was obtained by oxygen implosion in situ rolling up Pt/RGO, using Pt as catalyst for decomposition of hydrogen peroxide under ultrasonication. The as-obtained Pt/RGOS was characterized by means of transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffraction (XRD) and BET. Electrochemical voltammetry and steady-state chronoamperometry methods were used to evaluate the electrochemical active surface area and electrocatalytic activity in methanol oxidation. The results show that Pt/RGOS possess tubular structure with the diameter sizes ranging from10to100nm and different interlayer spaces and channels, Pt NPs with average particle diameter of3nm are uniformly dispersed among them. Compare with Pt/RGO, Pt/RGOS is not oxidized by oxygen bubbles in experimental operation process. BET results exhibit the Pt/RGOS possesses higher specific surface area and broader pore size range (188m2/g,25nm～45nm) than Pt/RGO (122m2/g,30nm～38nm). It is1.54times higher than Pt/RGO. Additionally, the electrocatalytic performance of Pt/RGOS for methanol oxidation was evaluated, and the results show that the Pt/RGOS possesses significantly higher electrocatalytic activity and stability than the Pt/RGO.(2) CNTs wrapped with nitrogen-doped carbon layer (N@CNTs) were synthesized by carbonized dopamine coated CNTs via spontaneous oxidative polymerization. Using N@CNTs as support, Pt or PtRu NPs with high dispersion and small particle size were successfully supported on the N@CNTs surface by a microwave assisted polyol reduction method and the obtained products were used as electrocatalysts for methanol oxidation. The N@CNTs was characterized by FTIR, Raman spectroscopy and elemental analysis. The micrographs of Pt/N@CNTs and PtRu/N@CNTs nanohybrids and their electrocatalytic properties for methanol oxidation were characterized by TEM and CV, respectively. The result show the CNTs surface was uniformly coated with dopamine, N@CNTs retain the structure of CNTs and the content of nitrogen element in N@CNTs is1.63wt.%. Pt (PtRu) NPs with an average diameter of ca.2.06nm (1.92nm) were highly dispersed on N@CNTs surface. Comparing Pt/CNTs-AO and PtRu/CNTs-AO catalysts, Pt/CN@CNTs and PtRu/N@CNTs catalysts have better electrocatalytic activity and long-term stability toward methanol electrooxidation. |
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