School of Applied Sciences, RMIT University, GPO Box 2476V, Melbourne, VIC 3001, Australia.
Nanoscale. 2012 Oct 21;4(20):6298-306. doi: 10.1039/c2nr31409f.
The fabrication of nanostructured bimetallic materials through electrochemical routes offers the ability to control the composition and shape of the final material that can then be effectively applied as (electro)-catalysts. In this work a clean and transitory hydrogen bubble templating method is employed to generate porous Cu-Au materials with a highly anisotropic nanostructured interior. Significantly, the co-electrodeposition of copper and gold promotes the formation of a mixed bimetallic oxide surface which does not occur at the individually electrodeposited materials. Interestingly, the surface is dominated by Au(I) oxide species incorporated within a Cu(2)O matrix which is extremely effective for the industrially important (electro)-catalytic reduction of 4-nitrophenol. It is proposed that an aurophilic type of interaction takes place between both oxidized gold and copper species which stabilizes the surface against further oxidation and facilitates the binding of 4-nitrophenol to the surface and increases the rate of reaction. An added benefit is that very low gold loadings are required typically less than 2 wt% for a significant enhancement in performance to be observed. Therefore the ability to create a partially oxidized Cu-Au surface through a facile electrochemical route that uses a clean template consisting of only hydrogen bubbles should be of benefit for many more important reactions.
通过电化学途径制造纳米结构的双金属材料具有控制最终材料组成和形状的能力，然后可以将其有效地用作（电）催化剂。在这项工作中，采用了清洁且短暂的氢气泡模板法来生成具有高度各向异性纳米结构内部的多孔 Cu-Au 材料。重要的是，铜和金的共电沉积促进了混合双金属氧化物表面的形成，而在单独电沉积的材料中则不会发生这种情况。有趣的是，表面主要由 Au(I)氧化物物种组成，这些物种嵌入在 Cu(2)O 基质中，对于工业上重要的（电）催化还原 4-硝基苯酚非常有效。据推测，氧化金和铜物种之间发生了亲金相互作用，这稳定了表面，防止了进一步氧化，并促进了 4-硝基苯酚与表面的结合，提高了反应速率。另一个好处是，只需使用仅由氢气泡组成的清洁模板，通过简单的电化学途径即可创建部分氧化的 Cu-Au 表面，通常只需不到 2wt%的金负载量即可观察到性能的显著提高。因此，通过使用仅由氢气泡组成的清洁模板，通过简单的电化学途径创建部分氧化的 Cu-Au 表面的能力应该对许多更重要的反应都有好处。
