UV-light induced solid-phase photodegradation in PANI nanocomposites

Hybrid polyaniline (PANI) nanocomposites were prepared by chemical oxidative polymerization of aniline in the presence of different metal oxide nanoparticles (TiO2 in rutile and anatase forms, SnO2). Influence of the near ultraviolet (UV) light on synthesized materials properties and possibility of polymer phase photocatalytic degradation were investigated. Specifically, we have studied the nanocomposites' properties before and after the UV exposition by UV-Vis spectroscopy, thermogravimetric analysis and conductivity measurements. The obtained results suggest that synthesized materials undergo solid-state photodegradation depending on the energy gap between PANI LUMO and metal oxides conduction band. A possible photodegradation mechanism based on the sensitizing effect by PANI is proposed.