Nature and properties of pure and Nb-doped TiO sub 2 ceramic membranes affecting the photocatalytic degradation of 3-chlorosalicylic acid as a model of halogenated organic compounds

Journal Article · Sun Mar 01 00:00:00 EST 1992 · Journal of Catalysis; (United States)

DOI:https://doi.org/10.1016/0021-9517(92)90207-X· OSTI ID:7202436

Sabate, J; Anderson, M A; Kikkawa, H; Xu, Q; Hill, Jr, C G ^[1]; Cervera-March, S ^[2]

---

1. Univ. of Wisconsin, Madison (United States)
2. Univ. of Barcelona (Spain)

Pure and Nb-doped TiO{sub 2} ceramic membranes supported on glass were prepared by sol-gel techniques. When irradiated with near-UV light, these membranes brought about the photocatalytic degradation of 3-chlorosalicylic acid (3-CSA). Relationships between preparation conditions and the characteristics and efficiencies of the different membranes have been inferred. The changes in the physical-chemical characteristics of these membranes when they are fired at high temperatures are retarded by both the Nb-doping and the coating on glass supports. Doping does not improve the rate of degradation of 3-CSA, despite the fact that light absorbance is higher. The increase of firing temperature causes an increase in the size of membrane particles and a remarkable drop in the specific surface area, resulting in a substantial decrease in photochemical efficiency. A discussion based on the hypothesis of e/h recombination at grain boundaries and point defects of the membranes is presented.

• DOE Contract Number: AS07-86ID12626
• OSTI ID: 7202436
• Journal Information: Journal of Catalysis; (United States), Vol. 134:1; ISSN 0021-9517
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
36 MATERIALS SCIENCE
MEMBRANES
CRYSTAL STRUCTURE
HEAT TREATMENTS
NIOBIUM
CATALYTIC EFFECTS
ORGANIC CHLORINE COMPOUNDS
DECOMPOSITION
PHOTOCHEMICAL REACTIONS
TITANIUM OXIDES
CATALYST SUPPORTS
CATALYSTS
CERAMICS
CHEMICAL PREPARATION
CHEMICAL PROPERTIES
COMPARATIVE EVALUATIONS
DOPED MATERIALS
EFFICIENCY
GLASS
GRAIN BOUNDARIES
GROUND WATER
HYDROGEN PRODUCTION
IRRADIATION
PARTICLE SIZE
PHYSICAL PROPERTIES
POINT DEFECTS
SALICYLIC ACID
SURFACE AREA
ULTRAVIOLET RADIATION
USES
VARIATIONS
WATER TREATMENT
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
CRYSTAL DEFECTS
ELECTROMAGNETIC RADIATION
ELEMENTS
EVALUATION
HYDROGEN COMPOUNDS
HYDROXY ACIDS
MATERIALS
METALS
MICROSTRUCTURE
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RADIATIONS
SIZE
SURFACE PROPERTIES
SYNTHESIS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
WATER
400500* - Photochemistry
360201 - Ceramics
Cermets
& Refractories- Preparation & Fabrication