Chemical Engineering Journal, Vol.249, 48-53, 2014
The effect of photonic band gap on the photo-catalytic activity of nc-TiO2/SnO2 photonic crystal composite membranes
nc-TiO2/SnO2 photonic crystal composite membranes were prepared by depositing nanocrystalline TiO2 layers on top of inverse opal SnO2 photonic crystals films. The photonic band gap of the SnO2 photonic crystals layer was tuned by changing the particles size of polystyrene microspheres. Photons trapped in the SnO2 photonic crystal layer are more effectively absorbed by TiO2 at the TiO2/SnO2 interface creating photoelectrons that assist in oxidation reactions. It was shown that the closer the photonic band gap of the phonic crystals layers matches the electronic band gap of TiO2 catalyst layer, the higher the photocatalytic activity of the composite membranes. The photo-activity of TiO2 can be enhanced by the synergistic effect of photonic crystal light localization at the SnO2/TiO2 interface. (C) 2014 Elsevier B.V. All rights reserved.