AVS 53rd International Symposium
    Nanometer-scale Science and Technology Thursday Sessions
       Session NS-ThP

Paper NS-ThP22
Evaluation of Immobilization Techniques on the Performance of Nanocrystalline TiO2-Polymer Composite Films

Thursday, November 16, 2006, 5:30 pm, Room 3rd Floor Lobby

Session: Nanoscale Science and Technology Poster Session
Presenter: E. Cruz, Sandia National Laboratories - Lawrence Berkeley National Laboratory, ALS division
Authors: E. Cruz, Sandia National Laboratories - Lawrence Berkeley National Laboratory, ALS division
B.A. Simmons, Sandia National Laboratories
Correspondent: Click to Email
Titanium dioxide (TiO2) has been used extensively over the years as a very effective photocatalyst capable of purifying water from organic contaminants. In a slurry of free particles and liquids, however, it is complex and costly to remove the titanium dioxide from the purified water effectively. This study investigates the immobilization of titanium dioxide on a variety of robust mesh structures with numerous techniques that can be used repeatedly for water purification operations. Various deposition methods and substrate combinations are presented and evaluated in terms of degradation efficiency of a mock pollutant. Scanning electron microscope (SEM) micrographs reveal the morphological characteristics of the TiO2-matrix support and the nature of the solid-liquid interface. Mechanical stability and robustness of the TiO2 support structures will also be discussed as a function of lifetime and durability. In our experiments, a flow-thru cell is used to contain the TiO2-matrix support. A pump-manifold system is then utilized to introduce the mock contaminated water that contains the dye methyl orange. This flow thru cell is irradiated at 300-nm, 350-nm and 419-nm wavelengths at different time intervals with different incident fluxes of light. Methyl orange degradation is evaluated using UV-Vis spectroscopy as a measure of the overall photocatalytic activity of the immobilized TiO2. We have also investigated the impact of doped TiO2 in terms of activity and wavelength dependence. The immobilized TiO2 films were observed to be very efficient decontamination substrates.