Construction of three-dimensional hierarchical Pt/TiO2@C nanowires with enhanced methanol oxidation properties |
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Affiliation: | 1. Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP 14040-901, Brazil;2. Universidade Federal do Triângulo Mineiro, Campus Universitário de Iturama, Iturama, MG 38280-000, Brazil |
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Abstract: | Three-dimensional (3D) hierarchical Pt/TiO2@C core-shell nanowire networks with high surface area have been constructed via wet chemical approaches. The 3D TiO2 nanowire framework was in situ synthesized within a porous titanium foam by hydrothermal method followed by carbon coating and self-assembled growth of ultrathin Pt nanowires. Structural characterization indicates that single crystalline ultrathin Pt nanowires of 3–5 nm in diameter were vertically distributed on the anatase TiO2 nanowires covered with a 2–4 nm thin carbon layer. The 3D hierarchical Pt/TiO2@C nanostructure demonstrates evidently higher catalytic activities towards methanol oxidation than the commercial Pt/C catalyst. The catalytic current density of the hierarchical catalyst is 1.6 times as high as that of the commercial Pt/C, and the oxidation onset potential (0.35 V vs. Ag/AgCl) is more negative than the commercial one (0.46 V vs. Ag/AgCl). Synergistic effect between the ultrathin Pt nanowires and the TiO2@C core-shell nanostructure accounts for the enhanced catalytic properties, which can be determined by X-ray photoelectron spectroscopy (XPS) investigation. The obtained hierarchical Pt/TiO2@C nanowire networks promise great potential in producing anode catalysts for direct methanol fuel cells applications. |
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Keywords: | Pt nanowires Titanium oxide Hierarchical Carbon coating Methanol oxidation |
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