Titanium dioxide-coated silica waveguides for the photocatalytic oxidation of formic acid in water

Journal Article · Tue Jun 15 00:00:00 EDT 1999 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es980817g· OSTI ID:6406769

Miller, L W; Tejedor-Tejedor, M I; Anderson, M A ^[1]

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1. Univ. of Wisconsin, Madison, WI (United States). Water Chemistry Program

Photooxidation of organic compounds on the surface of titanium dioxide (TiO[sub 2]) is a potential method of removing organic pollutants from water. By coating TiO[sub 2] on transparent substrates and illuminating the catalyst with internally reflected light, it may be possible to increase the amount of illuminated photocatalyst in a given reactor volume. Planar, silica internal reflection elements (IREs) were coated with thin, porous, nanoparticulate films of TiO[sub 2]. UV-visible internal reflection spectroscopy was performed in order to determine that visible and near-UV light propagated through the modified IREs in an attenuated total reflection (ATR) mode. The TiO[sub 2]-coated IREs were employed in a photocatalytic reactor, and their ability to oxidize formic acid was assessed. Apparent quantum yields and quantum efficiencies of formic acid oxidation as a function of catalyst film thickness and incident angles of internally propagation UV light (310--380 nm) were determined. Quantum efficiency was enhanced when UV light propagated through the TiO[sub 2]-coated waveguide in an ATR mode. Photocatalytic reactors based on waveguide-supported TiO[sub 2] films operating in an ATR mode may utilize light more effectively than reactors based on direct irradiance of TiO[sub 2] and could facilitate the scale-up of photocatalytic oxidation processes for commercial remediation applications.

• OSTI ID: 6406769
• Journal Information: Environmental Science and Technology, Vol. 33:12; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
CATALYSIS
FORMIC ACID
OXIDATION
PHOTOCHEMICAL REACTIONS
REMEDIAL ACTION
SILICA
TITANIUM OXIDES
ULTRAVIOLET RADIATION
WATER POLLUTION CONTROL
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
CONTROL
ELECTROMAGNETIC RADIATION
MINERALS
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
POLLUTION CONTROL
RADIATIONS
SILICON COMPOUNDS
SILICON OXIDES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
540220* - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)
540320 - Environment
Aquatic- Chemicals Monitoring & Transport- (1990-)