Molecular mechanisms of photoinduced oxygen evolution, PL emission, and surface roughening at atomically smooth (110) and (100) n-TiO2 (rutile) surfaces in aqueous acidic solutions
Molecular mechanisms of photoinduced oxygen evolution, PL emission, and surface roughening at atomically smooth (110) and (100) n-TiO2 (rutile) surfaces in aqueous acidic solutions
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DOI：
10.1021/ja053252e
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发表时间：
2005-09-21
影响因子：
15
通讯作者：
Nakato, Y
中科院分区：
文献类型：
--
作者：
Nakamura, R;Okamura, T;Nakato, Y
成功制备了原子级光滑稳定的（110）和（100）TiO_2（金红石）表面，结合原位光致发光（PL）和光电流测量以及原子力显微镜（AFM）检测，使我们能够对TiO_2（金红石）表面光析氧的分子机制及其相关过程进行系统研究，其对于太阳能水分解和光催化环境清洁是重要的。研究表明，各种表面过程和性质，如平带电位（U-fb），光谱和强度的光致发光从氧光致反应的前体，和光致表面粗糙化，都有很强的依赖于原子级结构的TiO 2表面。最重要的是，所有的结果都是基于我们最近提出的新的机制，即氧的光生反应是由H_2O分子亲核攻击表面陷阱空穴引发的，从而为它提供了有力的证据。本工作阐明了TiO_2表面光生初级过程的分子机制，将提供与水溶液接触的金属氧化物上的光反应的典型模型。
The success in preparing atomically smooth and stable (110) and (100) TiO2 (rutile) surfaces, combined with in situ photoluminescence (PL) and photocurrent measurements as well as atomic force microscopic (AFM) inspection, has enabled us to make systematic studies on molecular mechanisms of oxygen photoevolution and related processes on TiO2 (rutile), which are important for solar water splitting and photocatalytic environmental cleaning. The studies have revealed that various surface processes and properties, such as the flat-band potential (U-fb), the spectrum and intensity of the PL from a precursor of the oxygen photoevolution reaction, and photoinduced surface roughening, have all strong dependences on the atomic-level structure of the TiO2 surface. Importantly, all the results have been explained on the basis of our recently proposed new mechanism that the oxygen photoevolution reaction is initiated by a nucleophilic attack of an H2O molecule to a surface-trapped hole, thus giving confirmative evidence to it. The molecular mechanisms for photoinduced primary processes at the TiO2 surface, clarified in the present work, will provide a typical model for photoreactions on metal oxides in contact with aqueous solutions.