Toward photochemistry of integrated heterogeneous systems

Abstract

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.

Rotational Symmetry Effects on Multibody Lateral Interactions between Co-Adsorbates at Heterogeneous Interfaces

“…H eterogeneous interfaces�gas or liquid contacting a solid surface�are important for a wide range of applications, including catalysis, 1−3 semiconductors, 4,5 photochemistry, 6,7 and energy storage systems. 8,9 The material properties of such interfaces can be tuned via chemical adsorption.…”

“…Heterogeneous interfacesgas or liquid contacting a solid surfaceare important for a wide range of applications, including catalysis, − semiconductors, , photochemistry, , and energy storage systems. , The material properties of such interfaces can be tuned via chemical adsorption. , However, precise control of surface material properties and chemical adsorption/desorption processes is complicated via nanoscale lateral interactions between coadsorbates, , which govern adsorbate coverage and configuration and ultimately the thermodynamic and kinetic behaviors of the interface.…”