New insights into electronic and geometric effects in the enhanced photoelectrooxidation of ethanol Using ZnO nanorod/ultrathin Au nanowire hybrids.
New insights into electronic and geometric effects in the enhanced photoelectrooxidation of ethanol Using ZnO nanorod/ultrathin Au nanowire hybrids.
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DOI：
10.1021/ja5059444
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发表时间：
2014-10
影响因子：
15
通讯作者：
A. Leelavathi;G. Madras;N. Ravishankar
中科院分区：
文献类型：
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作者：
A. Leelavathi;G. Madras;N. Ravishankar
燃料电池中有机小分子的氧化是一种可行的能源生产方法。然而，关键问题是开发合适的催化剂，这些催化剂在操作过程中表现出高效率并保持稳定。在这里，我们证明了胺改性的ZnO纳米棒上生长的纳米线的氧化Au作为一个优秀的催化剂乙醇。我们发现，油胺的ZnO纳米棒的改性不仅修改了电子结构有利，但也用于锚的纳米棒上的Au纳米线。与裸Au纳米线相比，在低得多的电位下，有利于乙醇氧化所必需的OH（-）物质在Au纳米线上的吸附，从而产生高活性。虽然ZnO在正常条件下显示出可忽略的电催化活性，但在光照射下活性显著增强。我们证明了ZnO/Au纳米线混合物的光电催化活性的协同增强，并提供这种增强的电子和几何效应的基础上的机制解释。开发的原则是适用于调整其他金属/半导体混合动力车的性能与潜在的有趣的应用超出燃料电池的应用在这里展示。
Oxidation of small organic molecules in a fuel cell is a viable method for energy production. However, the key issue is the development of suitable catalysts that exhibit high efficiencies and remain stable during operation. Here, we demonstrate that amine-modified ZnO nanorods on which ultrathin Au nanowires are grown act as an excellent catalyst for the oxidation of ethanol. We show that the modification of the ZnO nanorods with oleylamine not only modifies the electronic structure favorably but also serves to anchor the Au nanowires on the nanorods. The adsorption of OH(-) species on the Au nanowires that is essential for ethanol oxidation is facilitated at much lower potentials as compared to bare Au nanowires leading to high activity. While ZnO shows negligible electrocatalytic activity under normal conditions, there is significant enhancement in the activity under light irradiation. We demonstrate a synergistic enhancement in the photoelectrocatalytic activity of the ZnO/Au nanowire hybrid and provide mechanistic explanation for this enhancement based on both electronic as well as geometric effects. The principles developed are applicable for tuning the properties of other metal/semiconductor hybrids with potentially interesting applications beyond the fuel cell application demonstrated here.