Representative examples of infrared spectroscopy uses in semiconductor photocatalysis

In the domain of semiconductor photocatalysis, infrared spectroscopy is a technique able to provide information inter alia upon: the generation, accumulation, scavenging and/or trapping of electronic charges under band-gap irradiation; the surface radicals existing during or after irradiation; the irradiation effects on the interactions of the surface with water; surface species not observed in the fluid phase; the texture, structure and surface properties of photocatalysts and photocatalytic coatings. In practice, the challenges are to achieve conditions as close as possible to those of the photocatalytic reactions, especially satisfactory irradiation of the photocatalyst by both the exciting photons and the infrared beam. As usual in infrared spectroscopy, labeled molecules can be employed to ascertain the attributions of the vibrational bands. Obviously, time-resolved infrared spectroscopy is extremely useful regarding the basic photocatalytic mechanisms. (C) 2013 Elsevier B.V. All rights reserved.