Designed nanostructured pt film for electrocatalytic activities by underpotential deposition combined chemical replacement techniques.
Designed nanostructured pt film for electrocatalytic activities by underpotential deposition combined chemical replacement techniques.
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DOI：
10.1021/jp051612e
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发表时间：
2005-07
期刊：
影响因子：
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通讯作者：
Minghua Huang;Yongdong Jin;Heqing Jiang;Xuping Sun;Hongjun Chen;Baifeng Liu;E. Wang;S. Dong
中科院分区：
文献类型：
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作者：
Minghua Huang;Yongdong Jin;Heqing Jiang;Xuping Sun;Hongjun Chen;Baifeng Liu;E. Wang;S. Dong
在玻碳电极上通过交替多次欠电位沉积（UPD）Ag，然后通过Pt（II）阳离子的氧化还原置换反应，制备了多层Pt覆盖层修饰的Pt纳米颗粒（MD-Pt overlayer/PtNPs）膜。用循环伏安法表征了薄膜的线性生长。原子力光谱（AFM）提供了纳米结构的Pt膜的表面形貌。旋转圆盘电极（RDE）和旋转环-圆盘电极（RRDE）伏安法表明，MD-Pt/PtNPs膜在空气饱和的0.1 M H2SO 4中可以催化O（2）还原为H2O，还原过程几乎为4电子。由此制备的Pt膜表现为新型的纳米结构的电催化剂，用于分子氧还原和析氢反应（HER），具有增强的电催化活性，在还原峰电位和峰电流方面，当与块状多晶Pt电极相比时。此外，值得注意的是，在多次置换循环后，电催化活性显著提高，尽管由于氧化还原-氧化还原置换技术的固有特征，与预修饰的PtNP相比，Pt的增加量非常低。换句话说，通过对催化剂表面进行剪裁，可以在不使用大量Pt的情况下显著提高催化剂的电催化活性。这些特征可以提供一种有趣的方式来生产具有可靠的催化性能以及降低成本的Pt催化剂。
Multiple-deposited Pt overlayer modified Pt nanoparticle (MD-Pt overlayer/PtNPs) films were deliberately constructed on glassy carbon electrodes through alternately multiple underpotential deposition (UPD) of Ag followed redox replacement reaction by Pt (II) cations. The linear and regular growth of the films characterized by cyclic voltammetry was observed. Atomic force spectroscopy (AFM) provides the surface morphology of the nanostructured Pt films. Rotating disk electrode (RDE) voltammetry and rotating ring-disk electrode (RRDE) voltammetry demonstrate that the MD-Pt overlayer/PtNPs films can catalyze an almost four-electron reduction of O(2) to H(2)O in air-saturated 0.1 M H(2)SO(4). Thus-prepared Pt films behave as novel nanostructured electrocatalysts for dioxygen reduction and hydrogen evolution reaction (HER) with enhanced electrocatalytic activities, in terms of both reduction peak potential and peak current, when compared to that of the bulk polycrystalline Pt electrode. Additionally, it is noted that after multiple replacement cycles, the electrocatalytic activities improved remarkably, although the increased amount of Pt is very low in comparison to that of pre-modified PtNPs due to the intrinsic feature of the UPD-redox replacement technique. In other words, the electrocatalytic activities could be improved markedly without using very much Pt by the technique of tailoring the catalytic surface. These features may provide an interesting way to produce Pt catalysts with a reliable catalytic performance as well as a reduction in cost.