title: Preparation and application of nanoglued binary titania-silica aerogel.
abstract: Nanoglued binary titania (TiO2)-silica (SiO2) aerogel, as a novel type of photocatalyst, has been synthesized on glass substrates. Using an about-to-gel SiO2 sol as nanoglue, anatase TiO2 aerogel was immobilized into a three-dimensional mesoporous network of the SiO2. Factorial designs were employed to optimize both TiO2 aerogel and binary TiO2-SiO2 aerogel synthesis. Characterization of the as-prepared TiO2 and binary samples by surface area, porosity, and surface chemical composition showed that the photocatalysts were high-surface-area nanoporous materials, with a Ti4+ valency. The binary aerogel exhibited high photocatalytic activity for the degradation of methylene blue (MB) under simulated solar light; the reaction followed the pseudo first-order Langmuir-Hinshelwood (L-H) kinetic model. Fluorescence spectroscopy revealed that the hydroxyl (*OH) radical was formed during the illumination of the binary TiO2-SiO2 aerogel in a solution of probe molecules, which corroborates the probable mechanism of hydroxyl radical oxidation of contaminants in photocatalytic reactions.
authors.affiliation: Department of Civil and Environmental Engineering, Temple University, 1947 North 12th Street, Philadelphia, PA 19122, United States.
authors.forename: Liang
authors.initials: L
authors.lastname: Luo
authors.forename: Adrienne T
authors.initials: AT
authors.lastname: Cooper
authors.forename: Maohong
authors.initials: M
authors.lastname: Fan
mesh_terms: D000269:Adhesives / Q000032:analysis* / Q000737:chemistry*; D000336:Aerosols / Q000737:chemistry; D002384:Catalysis; D007700:Kinetics; D015394:Molecular Structure; D049329:Nanostructures / Q000032:analysis / Q000737:chemistry*; D010777:Photochemistry; D012822:Silicon Dioxide / Q000032:analysis* / Q000737:chemistry*; D013057:Spectrum Analysis; D014025:Titanium / Q000032:analysis* / Q000737:chemistry*
chemical_list: D000269:Adhesives; D000336:Aerosols; C009495:titanium dioxide; D012822:Silicon Dioxide; D014025:Titanium