Thermal activation process of Au/TiO2 system: a molecular spectroscopy study

Abstract

The activation process of Au nanoparticles deposited on TiO₂ (Au/TiO₂) was studied by in situ diffuse reflectance UV-VIS and IR spectroscopy. The deposition–precipitation method with urea was used to support the gold nanoparticle precursor (AuPrs) on TiO₂ Degussa P25 and the activation process was carried out in H₂–Ar atmosphere. The results shows the existence of strong correlations during the different stages of thermal activation which include the decomposition of the Au complex delivering molecular reactive species, the formation of metallic AuNPs and the change in the effective optical bandgap of the TiO₂ support as a result of charge transfer processes.