Molecular Structure of a Mineral/Water Interface: Effects of Surface NanoRoughness of -Al2O3 (0001)
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- 作者：Bjö ; rn Braunschweig ; Stephan Eissner ; Winfried Daum
- 刊名：Journal of Physical Chemistry C
- 出版年：2008
- 出版时间：February 14, 2008
- 年：2008
- 卷：112
- 期：6
- 页码：1751 - 1754
- 全文大小：302K
- 年卷期：v.112,no.6(February 14, 2008)
- ISSN：1932-7455
文摘
Surface disorder on a nanometer scale is shown to have fundamental influence on the molecular structure of
-Al2O3(0001)/water interfaces which have been studied by sum-frequency vibrational spectroscopy. On roughsurfaces, we observe isolated surface hydroxyl groups which do not couple to the network of hydrogen-bonded water molecules of the interface and which we assign to aluminol groups in hydrophobic nanoporesof the surface. The pH dependence of O-H stretching vibrations of water molecules at the rough interfaceis distinctly different from that of an atomically smooth interface and points to different pK values fordeprotonation of surface hydroxyl groups at defect sites and regular terrace sites.
-Al2O3(0001)/water interfaces which have been studied by sum-frequency vibrational spectroscopy. On roughsurfaces, we observe isolated surface hydroxyl groups which do not couple to the network of hydrogen-bonded water molecules of the interface and which we assign to aluminol groups in hydrophobic nanoporesof the surface. The pH dependence of O-H stretching vibrations of water molecules at the rough interfaceis distinctly different from that of an atomically smooth interface and points to different pK values fordeprotonation of surface hydroxyl groups at defect sites and regular terrace sites.