使用光电子谱学探测氧化 (TiO(2)) (n) (((-) (n = 1-10) 的电子结构和带隙演变
1Department of Physics, Washington State University, 2710 University Drive, Richland, Washington 99354, USA.
Journal of the American Chemical Society
|February 16, 2007
概括
使用阳离子光电谱学研究了二氧化 (TiO2) 集群的电子结构和带隙. 带间隙大小稳定为具有七个或更多单位的TiO2集群,为光催化提供了洞察力.
科学领域:
- 材料科学 材料科学 材料科学
- 物理化学 物理化学
- 表面科学是一门学科.
背景情况:
- 二氧化 (TiO2) 是一种重要的宽带间隙半导体,广泛用于光催化.
- 了解TiO2集群的电子结构和尺寸依赖性质对于优化其催化性能至关重要.
研究的目的:
- 通过实验研究 (TiO2) n集群的电子结构.
- 为了确定TiO2集群的带隙如何随着大小而演变.
- 为了解TiO2表面缺陷和光催化提供分子模型.
主要方法:
- 阳离子光电子光谱学 (PES) 用于对n = 1-10的 (TiO2) n-集群进行研究.
- 实验使用193nm (6.424 eV) 和157nm (7.866 eV) 的光子能量进行.
- 在157纳米处的高光子能量可以清楚地观察较大的星团的带隙.
主要成果:
- TiO2集群的带间隙在n < 7时表现出强大的尺寸依赖.
- 带间距快速接近n = 7的批量极限,并保持不变到n = 10.
- 广泛的PES特征表明,由于电子定位,阴离子和中性之间发生了显著的几何变化.
结论:
- 该研究显示,TiO2集群的带隙在n=7.7的大小时稳定.
- 在 (TiO2) n-集群 (n>1) 中的额外电子定位在一个三坐标的Ti原子上,形成一个Ti3+位点.
- 这些发现使TiO2集群成为研究表面缺陷和光催化机制的有价值的分子模型.
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