Weighting the influence of TiO2 anatase/brookite ratio in TiO2–Ag porous nanocomposites on visible photocatalytic performances

Nanocomposites based on TiO2 aerogel and Ag nanoparticles have been successfully obtained through different synthesis methods and their specific surface areas have been determined by N2 sorption (BET method). The photocatalytic potential for salicylic acid degradation has been evaluated. It was found that under visible light irradiation, all synthesized nanocomposites exhibit higher photocatalytic activity than the commercially available Aeroxide P25. By correlating the structural parameters with the photocatalytic performances, it has been found that the Ag nanoparticles and brookite phase presence alongside the anatase play important roles on the visible photocatalysts behavior. For the Ag containing samples with mixed anatase–brookite phases, it has been observed that the visible photocatalytic performance decreases with the increase in brookite crystalline phase content. On the other hand, the addition of Ag nanoparticles results, as expected, in a clear enhancement of the visible photocatalytic activity.