Vicinal Rutile TiO2 Surfaces and Their Interactions with O2

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• 作者：Felix Rieboldt ; Ralf Bechstein ; Flemming Besenbacher ; Stefan Wendt
• 刊名：Journal of Physical Chemistry C
• 出版年：2014
• 出版时间：February 20, 2014
• 年：2014
• 卷：118
• 期：7
• 页码：3620-3628
• 全文大小：505K
• ISSN：1932-7455

文摘

Slightly miscut TiO₂(110) surfaces with high densities of step edges were studied by scanning tunneling microscopy (STM), temperature-programmed desorption (TPD), and ultraviolet photoemission spectroscopy (UPS). STM measurements provided information on the surface morphology and the density of defects and adstructures, whereas UPS measurements revealed information on the electronic structure and the surface reduction state before and after the conduction of O₂ TPD experiments. It was found that the presence of step edges and adstructures has a strong influence on the O₂鈥揟iO₂ interaction. The growth of TiO_x islands occurred in the same way on stepped surfaces as on flat TiO₂(110) surfaces, but the island densities were smaller. TPD measurements revealed that significantly less O₂ desorbed between 300 and 410 K from stepped surfaces than from surfaces with large terraces. Importantly, the stepped TiO₂ surfaces were characterized by clearly lower surface reduction states than flat TiO₂(110) surfaces.