Coverage-Dependent Structural Evolution in the Interaction of NO2 with Au{111}

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• 作者：Tianfu Zhang ; Marco Sacchi ; David A. King ; Stephen M. Driver
• 刊名：The Journal of Physical Chemistry C
• 出版年：2012
• 出版时间：March 8, 2012
• 年：2012
• 卷：116
• 期：9
• 页码：5637-5645
• 全文大小：495K
• 年卷期：v.116,no.9(March 8, 2012)
• ISSN：1932-7455

文摘

We have used low-temperature STM, together with DFT calculations incorporating the effects of dispersion forces, to study from a structural point of view the interaction of NO₂ with Au{111} surfaces. NO₂ adsorbs molecularly on Au{111} at 80 K, initially as small, disordered clusters at the elbows of the type-x reconstruction lines of the clean-surface herringbone reconstruction, and then as larger, ordered islands on the fcc regions. Within the islands, the NO₂ molecules define a (鈭? 脳 2)rect. superlattice, for which we evaluate structural models. By around 0.25 ML coverage, the herringbone reconstruction has been lifted, accompanied by the formation of Au nanoclusters, and the islands have coalesced. At this stage, essentially the whole surface is covered with an overlayer consisting predominantly of domains of the (鈭? 脳 2)rect. structure, but also containing less well-ordered regions. With further exposure, the degree of disorder in the overlayer increases; saturation occurs close to 0.43 ML.