Confinement-Induced Growth of Au Nanoparticles Entrapped in Mesoporous TiO2 Thin Films Evidenced by in Situ Thermo-Ellipsometry

摘要: Metal-porous oxide nanocomposites present great interest in optical devices and heterogeneous catalysis. For these applications, particle shape size control, as well accessibility, are critical aspects. In this work, gold nanoparticles (NPs) were infiltrated into mesoporous TiO2 thin films (MTTF) by an impregnation-reduction method. situ ellipsometry measurements performed during thermal treatment to follow real time the changes constants thickness of composites systems while being submitted continuous heating at different rates, from room temperature up 600 °C. Complementary characterization UV–visible spectrophotometry, grazing incident wide angle scattering (GIWAXS), X-ray reflectometry (XRR) performed. TEM microscopy was used analyze morphological composite after treatment. Our experiments demonstrate that coarsening starts temperatures below 200 °C through processes ripening parti...