A Photocatalytic Approach for the Reductive Decolorization of Textile Azo Dyes in Colloidal Semiconductor Suspensions

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...

Full description

Saved in:
Bibliographic Details
Published in:Langmuir 1994-06, Vol.10 (6), p.1767-1771
Main Authors: Vinodgopal, K, Bedja, Idriss, Hotchandani, Surat, Kamat, Prashant V
Format: Article
Language:English
Subjects:
140400 - Solar Energy- Environmental Aspects
140505 - Solar Energy Conversion- Photochemical, Photobiological, & Thermochemical Conversion- (1980-)
360606 - Other Materials- Physical Properties- (1992-)
400500 - Photochemistry
AZO COMPOUNDS
AZO DYES
CATALYSIS
CHALCOGENIDES
CHEMICAL REACTIONS
Chemistry
COLLOIDS
DECOMPOSITION
DISPERSIONS
DYES
ELECTROMAGNETIC RADIATION
ELECTRON TRANSFER
ELECTRONS
ELEMENTARY PARTICLES
Exact sciences and technology
FERMIONS
General and physical chemistry
INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY
LASERS
LEPTONS
MANAGEMENT
MATERIALS
MATERIALS SCIENCE
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
Photochemistry
PHOTOLYSIS
Physical chemistry of induced reactions (with radiations, particles and ultrasonics)
PROCESSING
RADIATIONS
REDUCTION
REFRACTORY METAL COMPOUNDS
SEMICONDUCTOR MATERIALS
SOLAR ENERGY
SUSPENSIONS
TITANIUM COMPOUNDS
TITANIUM OXIDES
TRANSITION ELEMENT COMPOUNDS
TRAPPING
TUNGSTEN COMPOUNDS
TUNGSTEN OXIDES
ULTRAVIOLET RADIATION
WASTE MANAGEMENT
WASTE PROCESSING
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:0743-7463
1520-5827
DOI:10.1021/la00018a024