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International Journal of Photoenergy
Volume 2012, Article ID 525727, 7 pages
http://dx.doi.org/10.1155/2012/525727
Research Article

Synthesis and Characterization of K-Ta Mixed Oxides for Hydrogen Generation in Photocatalysis

Institute of Chemical and Environment Engineering, West Pomeranian University of Technology, Szczecin, Pułaskiego 10, 70-322 Szczecin, Poland

Received 27 February 2012; Accepted 16 April 2012

Academic Editor: Ignazio Bellobono

Copyright © 2012 Beata Zielińska et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

K-Ta mixed oxides photocatalysts have been prepared by impregnation followed by calcination. The influence of the reaction temperature (450°C–900°C) on the phase formation, crystal morphology, and photocatalytic activity in hydrogen generation of the produced materials was investigated. The detailed analysis has revealed that all products exhibit high crystallinity and irregular structure. Moreover, two different crystal structures of potassium tantalates such as KTaO3 and K2Ta4O11 were obtained. It was also found that the sample composed of KTaO3 and traces of unreacted Ta2O5 (annealed at 600°C) exhibits the highest activity in the reaction of photocatalytic hydrogen generation. The crystallographic phases, optical and vibronic properties were examined by X-ray diffraction (XRD) and diffuse reflectance (DR) UV-vis and resonance Raman spectroscopic methods, respectively. Morphology and chemical composition of the produced samples were studied using a high-resolution transmission electron microscope (HR-TEM) and an energy dispersive X-ray spectrometer (EDX) as its mode.