Photocatalytic activity of Ag-substituted and impregnated nano-TiO2

Vinu, R and Madras, Giridhar (2009) Photocatalytic activity of Ag-substituted and impregnated nano-TiO2. In: Applied Catalysis A: General, 366 (1). pp. 130-140.

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Abstract

Ag-substituted (Ag sub) and Ag-impregnated (Ag imp), anatase phase nano-TiO2 have been synthesized by solution combustion technique and reduction technique, respectively. The catalysts were characterized extensively by powder XRD, TEM, XPS, FT-Raman, UV absorption, FT-IR, TGA, photoluminescence, BET surface area and isoelectric pH measurements. These catalysts were used for the photodegradation of dyes and for the selective photooxidation of cyclohexane to cyclohexanone. The photoactivities of the combustion-synthesized catalysts were compared with those of commercial Degussa P 25 (DP 25) TiO2, and Ag-impregnated DP 25 (Ag DP). For the photocatalytic degradation of dyes, unsubstituted combustion-synthesized TiO2 (CS TiO2) exhibited the highest activity, followed by 1% Ag imp and 1% Ag sub. For the photoconversion of cyclohexane, the total conversion of cyclohexane and the selectivity of cyclohexanone followed the order: 1% Ag sub > DP 25 > CS TiO2 > 1% Ag imp > 1% Ag DP. The kinetics of the photodegradation of dyes and of the photooxidation of cyclohexane were modeled using Langmuir–Hinshelwood rate equation and a free radical mechanism, respectively, and the rate coefficients were determined. The difference in activity values of the catalysts observed for these two reactions and the detailed characterization of these catalysts are described in this study.

Item Type:	Journal Article
Publication:	Applied Catalysis A: General
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science
Keywords:	Ag substitution;Ag impregnation;Combustion synthesis; Cyclohexane;Photooxidation;Rate coefficients
Department/Centre:	Division of Mechanical Sciences > Chemical Engineering
Date Deposited:	13 Dec 2009 10:54
Last Modified:	19 Sep 2010 05:46
URI:	http://eprints.iisc.ac.in/id/eprint/23679

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