Photocatalytic approach for the reductive decolorization of textile azo dyes in colloidal semiconductor suspensions

Journal Article · Wed Jun 01 00:00:00 EDT 1994 · Langmuir; (United States)

DOI:https://doi.org/10.1021/la00018a024· OSTI ID:6991143

Vinodgopal, K ^[1]; Bedja, I; Hotchandani, S ^[2]; Kamat, P V ^[3]

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1. Indiana Univ. Northwest, Gary, IN (United States)
2. Universite du Quebec a Trois Rivieres, Quebec (Canada)
3. Univ. of Notre Dame, IN (United States)

Two representative commercially used textile azo dyes, Acid Orange 7 and Direct Blue 1, have been decolorized using colloidal TiO[sub 2] and WO[sub 3] photocatalytic systems. Under UV irradiation, these dyes undergo rapid decolorization as they are reduced at the semiconductor surface by the trapped electrons. The trapping of electrons in irradiated semiconductor colloids and their participation in the dye reduction process have been probed by steady-state and laser flash photolysis techniques. The quantum efficiency for such a reductive process has been determined to be 4.7%. The rate constant for the electron transfer between the excited semiconductor colloid and the dye is of the order of 10[sup 8] M[sup [minus]1] s[sup [minus]1]. This photocatalytic decolorization approach has potential applications in the treatment of textile dye wastes. 28 refs., 8 figs.

• OSTI ID: 6991143
• Journal Information: Langmuir; (United States), Vol. 10:6; ISSN 0743-7463
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
AZO DYES
ELECTRON TRANSFER
PHOTOCHEMICAL REACTIONS
REDUCTION
ELECTRONS
TRAPPING
SEMICONDUCTOR MATERIALS
CATALYSIS
COLLOIDS
LASERS
PHOTOLYSIS
SUSPENSIONS
TITANIUM OXIDES
TUNGSTEN OXIDES
ULTRAVIOLET RADIATION
WASTE PROCESSING
AZO COMPOUNDS
CHALCOGENIDES
CHEMICAL REACTIONS
DECOMPOSITION
DISPERSIONS
DYES
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FERMIONS
LEPTONS
MANAGEMENT
MATERIALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PROCESSING
RADIATIONS
REFRACTORY METAL COMPOUNDS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TUNGSTEN COMPOUNDS
WASTE MANAGEMENT
140505* - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)
140400 - Solar Energy- Environmental Aspects
400500 - Photochemistry
360606 - Other Materials- Physical Properties- (1992-)