Versatile Model System for Studying Processes Ranging from Heterogeneous to Photocatalysis: Epitaxial RuO2(110) on TiO2(110)

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• 作者：Yunbin He ; Daniel Langsdorf ; Lei Li ; Herbert Over
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：February 5, 2015
• 年：2015
• 卷：119
• 期：5
• 页码：2692-2702
• 全文大小：912K
• ISSN：1932-7455

文摘

The binary model system RuO₂/TiO₂(110) can be prepared with single crystallinity and excellent control of the morphology of the RuO₂(110) nanoislands. The interface of RuO₂/TiO₂(110) is structurally well-defined since RuO₂ grows with the same lattice constants as TiO₂(110). The actual growth of RuO₂ on TiO₂(110) single crystals starts from square-shaped 3鈥? ML thick RuO₂ islands with narrow size and thickness distributions. After TiO₂(110) is completely covered by RuO₂, the further growth proceeds via a step flow mechanism, forming very large and flat RuO₂(110) terraces with well-defined thickness. Both the flat RuO₂(110) films and RuO₂(110) nanoislands are very reactive toward CO oxidation, and the RuO₂(110) nanoislands are robust in the redox reactions, i.e., easily recovering their morphology after reoxidation from the reduced state. The RuO₂/TiO₂(110) heterojunction forms a Schottky barrier of 1.4 eV which is important for photocatalysis.