Electrochemical Fabrication of Two-Dimensional Flower-like Pt Nanostructures for Methanol Electrocatalytic Oxidation
- 2014年第20卷 
采用恒电流电化学技术在玻碳基底上制得二维“花状”Pt纳米结构（2D FPNs）样品，所用的电解液为HAuCl4 + HClO4溶液，无需添加任何表面结构诱导的有机试剂，Pt纳米结构表面更“洁净”，有较高的反应活性. 扫描电子显微镜测试显示，2D FPNs样品是由球状纳米花构成，纳米叶子是构筑纳米花的最小单元. 通过控制电沉积时间可调控球状Pt纳米花数的密度. 高倍透射电子显微镜测试表明每个叶状纳米片沿着Pt(111)晶面定向生长. 甲醇电催化氧化活性与电沉积时间有关. 2D FPNs电极的甲醇的电催化活性稍高于商业Pt/C电极，却有更好的抗毒化能力，这可能归因于其特定的暴露晶面及表面的“洁净性”.Two-dimensional flower-like Pt nanostructures (2D FPNs) were fabricated on glassy carbon substrates by galvanostatical electrochemical technique. The electrolyte was the HAuCl4 + HClO4 aqueous solution without addition of any structure-directing organic reagent, which made as-prepared Pt nanostructures cleaner, exhibiting much higher reactivity. Scanning electron microscopic images revealed that 2D FPNs were spherical Pt nano-flowers constructed by the smallest building blocks, nano-leaves. The number density of spherical Pt nano-flowers can be tuned by controlling the electrodeposition time. High resolution transmission electron microscopic images indicated that each nano-leaf was formed by growing along Pt(111) direction. Electrocatalytic activities of as-prepared 2D FPNs were closely linked with the electrodeposition time. The electrocatalytic activity of 2D FPNs under the optimized electrodeposition time was slightly higher than that of the commercial Pt/C catalyst with much better tolerance to CO-like poisoning molecules. It may be attributed to the exposure of specified facets and the cleanness of surface.