Kyoto University, Graduate School of Science, Department of Chemistry, Kyoto 606-8502, Japan.
J Chem Phys. 2012 Sep 7;137(9):091705. doi: 10.1063/1.4746802.
This paper begins with describing the excitation mechanisms in surface photochemistry and nuclear dynamics of adsorbate induced by electronic excitation. An illustrative example is Cs adsorbate on a Cu(111) surface. This adsorption system shows drastic changes in the electronic structure with coverage; this allows us to examine different types of electronic excitations that stimulate nuclear motions of Cs. Remarks are made on challenges in photoinduced processes at well-defined surfaces: direct observations of adsorbate-substrate vibrational modes and photoinduced reactions between adsorbates. Then, the paper addresses some issues in more complex systems: metal-liquid interfaces and powdered photocatalysts of metal oxides. Photochemistry and photoinduced nuclear dynamics at metal-liquid interfaces have not been well explored. Studies on this subject may make it possible to bridge the gap between surface photochemistry and electrochemistry. Photocatalysis with powdered catalysts has been extensively studied and is still an active area, but our understanding of the mechanism of photocatalysis is far from satisfactory. Although complicated, the highly integrated systems provide an opportunity to extend our knowledge of surface photochemistry.
本文首先描述了表面光化学中的激发机制和电子激发诱导吸附物的核动力学。以 Cs 吸附在 Cu(111)表面为例，该吸附体系的电子结构随覆盖度发生剧烈变化，这使得我们能够研究不同类型的电子激发，以激发 Cs 的核运动。文中还提到了在明确定义的表面上进行光诱导过程的挑战：直接观察吸附物-衬底振动模式和吸附物之间的光诱导反应。然后，本文讨论了更复杂体系中的一些问题：金属-液相界面和金属氧化物的粉末光催化剂。金属-液相界面的光化学和光诱导核动力学尚未得到充分探索。对这一课题的研究可能有助于弥合表面光化学和电化学之间的差距。粉末催化剂的光催化已得到广泛研究，仍是一个活跃的领域，但我们对光催化机制的理解还远远不够。尽管复杂，但高度集成的体系为扩展我们对表面光化学的认识提供了机会。
