Sacrificial water photocleavage using Nb-doped $TiO_2$ fine particles under band gap irradiation

Kutty, TRN and Avudaithai, M (1990) Sacrificial water photocleavage using Nb-doped $TiO_2$ fine particles under band gap irradiation. In: International Journal of Hydrogen Energy, 15 (9). pp. 621-628.

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Abstract

Ultrafine powders of $TiO_2$ doped with $Nb^{5+}$ up to 10 mol% are produced by the hydrothermal procedure at 150–180 C and 1–4 MPa. Aqueous suspensions of these powders do not produce $H_2$ on band gap irradiation, even after Pt-loading. $H_2$ is evolved only in presence of a hole scavenger, such as EDTA. $H_2$ -evolution capacity of $TiO_2$ is enhanced up to $\sim$ 0.3 mol% Nb and reverses the trend at higher Nb-concentrations. $H_2$ -yield is not related to anatase/rutile phase content. The decrease in $H_2$ production with $TiO_2$:Nb is due to the Schottky type of defect centres with donor character, that are charge-compensatively formed in $TiO_2$ and act as electron traps. The accumulation of electrons in Nb-doped $TiO_2$ is supported by the electron paramagnetic resonance and the current potential measurements under illumination of the slurry electrode cells.

Item Type:	Journal Article
Publication:	International Journal of Hydrogen Energy
Publisher:	Pergamon Press plc.
Additional Information:	Copyright of this article belongs to International Association for Hydrogen Energy.
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	08 Feb 2008
Last Modified:	19 Sep 2010 04:41
URI:	http://eprints.iisc.ac.in/id/eprint/12702

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