Reversible conversion between AgCl and Ag in AgCl-doped RSiO3/2–TiO2 films prepared by a sol–gel technique

The reversible redox behavior exhibited by AgCl-doped organosilsesquioxane-titania gel films is studied. Films prepared by the sol–gel method show reversible color changes with blue laser irradiation and subsequent heat treatment, which is based on the formation of Ag and AgCl nanoparticles, respectively. Two-beam interference exposure experiments reveal that the films have potential to be applied as rewritable holographic materials. A large titania content is essential for the conversion of Ag to AgCl because it induces the Cl to remain near the Ag nanoparticles during blue laser irradiation, allowing the Cl to react with neighboring Ag nanoparticles to reform AgCl upon subsequent heat treatment.