Strontium tantalum oxides with perovskite-type structure: synthesis and dye photodecomposition properties
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In this work the preparation and photocatalytic properties of strontium tantalum oxides with perovskite-type structures are presented. The perovskite-type oxides were prepared by the sol–gel method and annealed at 800, 900 and 1,000 °C for 36 h. Before and after annealing the solids were characterized by XRD, N2 adsorption (BET), UV–visible (diffuse reflectance), FTIR, TGA–DTA, and SEM-EDS techniques. The X-ray diffraction patterns of the samples showed the coexistence of three strontium tantalate oxides, Sr2Ta2O7, SrTa4O11, and Sr5Ta4O15, the relative amounts of which were highly dependent on the annealing temperature. It has been proposed that the photoactivity of the oxides in the decomposition of crystal violet dye could be related to the proportion of the Sr2Ta2O7 phase in the annealed samples.
KeywordsPerovskite-type structure Sol–gel perovskite synthesis Crystal violet degradation Strontium tantalum oxide perovskite-type structure
The authors would like to thank to SEP-CONACYT (SEP-2003-C02-42910), SEMARNAT (2004-C01-394), and PAICYT-UANL (CA1248-06, CA1265-06) for financial support to this project. The authors also thank the CONACYT-KRF México-Korea Bilateral Cooperation Program (2007).
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