The Influence of the Au Nanoparticles Dimension on the Photocatalytic Performances of $TiO_2-Au$ Porous Composites

The influence of Au nanoparticles dimension on the photocatalytic performances of the $TiO_2$ aerogels-Au composites was evaluated. Structural and morphological peculiarities of the $TiO_2$ aerogel, unloaded and loaded with 5 and 22 nm Au nanoparticles, were studied by transmission electron microscopy technique, X-ray diffraction and $N_2$-sorption measurements. UV-Vis diffuse reflectance measurements were performed to determine the band gap energies. The photocatalytic activity was evaluated by monitoring the salicylic acid photodegradation. It was found that the Au nanoparticles promote the anatase phase crystallization and produce the decrease of the specific surface area and band gap energy values. The porous composite with the smallest Au nanoparticles dimension exhibits the best photocatalytic performances.