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), Journal Name: Langmuir; (United States) Vol. 10:6; ISSN LANGD5; ISSN 0743-7463
• Country of Publication: United States
• Language: English

Related Subjects

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36 MATERIALS SCIENCE
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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500 -- Photochemistry
AZO COMPOUNDS
AZO DYES
CATALYSIS
CHALCOGENIDES
CHEMICAL REACTIONS
COLLOIDS
DECOMPOSITION
DISPERSIONS
DYES
ELECTROMAGNETIC RADIATION
ELECTRON TRANSFER
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
LASERS
LEPTONS
MANAGEMENT
MATERIALS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PROCESSING
RADIATIONS
REDUCTION
REFRACTORY METAL COMPOUNDS
SEMICONDUCTOR MATERIALS
SUSPENSIONS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRAPPING
TUNGSTEN COMPOUNDS
TUNGSTEN OXIDES
ULTRAVIOLET RADIATION
WASTE MANAGEMENT
WASTE PROCESSING