Table of Contents Author Guidelines Submit a Manuscript
International Journal of Photoenergy
Volume 2013, Article ID 406158, 9 pages
http://dx.doi.org/10.1155/2013/406158
Research Article

Facile Preparation of Phosphotungstic Acid-Impregnated Yeast Hybrid Microspheres and Their Photocatalytic Performance for Decolorization of Azo Dye

College of Environmental Science and Engineering, Chang’an University, Xi’an 710054, China

Received 16 January 2013; Revised 9 April 2013; Accepted 9 April 2013

Academic Editor: Elias Stathatos

Copyright © 2013 Lan Chen and Bo Bai. 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

Phosphotungstic acid (HPW)-impregnated yeast hybrid microspheres were prepared by impregnation-adsorption technique through tuning pH of the aqueous yeast suspensions. The obtained products were characterized by field emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), X-ray diffraction (XRD), thermogravimetry-differential scanning calorimetry (TG-DSC), and ultraviolet-visible spectrophotometry (UV-Vis), respectively. FE-SEM and EDS ascertain that the HPW has been effectively introduced onto the surface of yeast, and the resulting samples retain ellipsoid shape, with the uniform size (length 4.5 ± 0.2 μm, width 3.0 ± 0.3 μm) and good monodispersion. XRD pattern indicates that the main crystal structure of as-synthesized HPW@yeast microsphere is Keggin structure. TG-DTA states that the HPW in composites has better thermal stability than pure HPW. Fourier transform infrared spectroscopy (FT-IR) elucidates that the functional groups or chemical bonds inherited from the pristine yeast cell were critical to the assembling of the composites. UV-Vis shows that the obtained samples have a good responding to UV light. The settling ability indicates that the hybrid microspheres possess an excellent suspension performance. In the test of catalytic activity, the HPW@yeast microsphere exhibits a high photocatalytic activity for the decoloration of Methylene blue and Congo red dye aqueous solutions, and there are a few activity losses after four cycles of uses.