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Influence of calcination on the microstructures and photocatalytic activity of potassium oxalate-doped TiO2 powders

Paper ID Volume ID Publish Year Pages File Format Full-Text
43043 45952 2008 13 PDF Available
Title
Influence of calcination on the microstructures and photocatalytic activity of potassium oxalate-doped TiO2 powders
Abstract

Potassium oxalate-doped TiO2 powders were prepared by the base-catalyzed sol–gel process with TiCl4 as a precursor and hexamethylenetetramine as basic agent. The influence of calcination on the structure and photocatalytic activity of the as-prepared TiO2 samples was investigated. The physical properties of the pre- and post-calcined materials were studied by X-ray diffraction spectroscopy, scanning electron microscopy, specific surface area, Fourier-transformed infrared spectroscopy, photoluminescence spectroscopy, and diffuse reflectance ultraviolet-visible spectroscopy. The photocatalytic activity of the products was evaluated by decolorizing methylene blue solutions and comparing them with a commercial TiO2 powder (Degussa P25). The optimum calcination temperature of 800 °C yielded samples with enhanced photocatalytic activity comparable to Degussa P25. On the other hand, the non-calcined TiO2 sample (amorphous phase with small amount of anatase phase) produced a better decolorization efficiency than did commercial P25, due to its excellent adsorptive properties with high concentrations of methylene blue solutions. More significantly, the dye adsorbed onto the surface of the non-calcined TiO2 sample could be removed by treating with hydrogen peroxide solution under UV irradiation. The regenerated TiO2 samples could be reused in the subsequent decolorization of methylene blue solution without a decline in decolorization efficiency compared with freshly prepared TiO2 samples, with even slightly better efficiency.

Graphical abstractThe uncalcined potassium oxalate-doped TiO2 has high adsorptivity power for dye solution at high concentration. Decolorization efficiencies were investigated for both the uncalcined and the calcined samples. The used uncalcined samples can be regenerated by H2O2 with UV irradiation and can be reused to decolorize dye solution again without loss of decolorizing efficiency.Figure optionsDownload full-size imageDownload as PowerPoint slide

Keywords
Titanium dioxide; Amorphous titanium dioxide; Sol–gel process; Calcinations; Methylene blue; Dye decolorization
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Influence of calcination on the microstructures and photocatalytic activity of potassium oxalate-doped TiO2 powders
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Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 338, Issues 1–2, 1 April 2008, Pages 87–99
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us