Fabrication of TiO2 Colloidal Crystal Films and Characterization of Their Photocatalytic Properties

Abstract

We have studied hydrolysis of organic alkyltitanate compounds and optimized reaction condition for synthesis of monodisperse titania (TiO2 colloidal particles with controlled size from nanometer to submicron. The synthesized TiO2 colloidal particles were further surface-modified with hydrophobic silane coupling agent. With the monodisperse hydrophobic particles, we fabricated TiO2 colloidal crystal thin films through transferring self-assembled colloidal crystal monolayer from water surface onto solid substrates. The TiO2 colloidal crystal films exhibit enhanced interaction with visible light. Consequently, in comparison with plain TiO2 particle thin film, the thin film with colloidal crystal structure shows enhanced photocatalytic activity, as evaluated through photodegradation of organic dye methyl orange in solution under simulated solar light.