Case Studies: Photoluminescence (PL) Spectroscopy

The chapter presents two representative case studies, which highlight the potentialities of photoluminescence (PL) spectroscopy for the study of photocatalytic systems at the molecular level in their working state. The first part of the chapter is devoted to the investigation of charge carrier dynamics in semiconductor photocatalysts (TiO2 and g-C3N4) by steady-state and ultrafast time-resolved PL, focusing also on the interaction with the semiconductor surface of key reactants in photocatalytic processes. The second part, on the other hand, describes single-site photocatalytic systems based on transition metal ions dispersed on silica supports, discussing in particular PL studies of NO photo-reduction by CO on Mo6+/SiO2 and preferential photo-oxidation of CO by O2 on Cr6+/MCM-41.