IR spectroscopy as a tool to investigate photocatalytic reactions at oxide surfaces

In the last years in situ and operando IR spectroscopies are emerging as powerful tools to directly investigate the processes occurring at the surface of oxide particles during photocatalytic reactions. This paper provides a concise overview of the most used acquisition modes (transmission, ATR and DRIFT) and the related experimental setups available to study reactions under UV irradiation. Subsequently a selection of significant applications will be presented, including photocatalytic reactions in gas phase and at the solid-liquid interface. The selected examples will highlight the effectiveness of IR spectroscopy in monitoring the evolution of the reaction intermediates and products at the photocatalyst surface. This approach allows to better understand the reaction mechanism and to derive the kinetic laws, expressed in terms of surface concentrations.