ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
The photocatalytic activity of samples of the new ceramic semiconductor, Na2ZrTi5O13 sol-gel, was studied using two different reactions, the decomposition (oxidation) of methylene blue and reduction-oxidation of Pb (II) from aqueous solutions at room temperature. We synthesised Na2Ti5ZrO13, which is isostructural to the family of compounds with general formula AnMTimO13, (A = Li, Na, K; M = Zr). These materials present a zig zag arrangement forming rectangular tunnelsin their structure. The synthesis of this compound was achieved by sol-gel technique using metalic alcoxides at two different pH, 3 and 9. The fresh gels were heat treated at 200°C, 400°C, 600°C and 800°C. The reaction products were characterized by X-ray diffraction (XRD), thermal analysis (DTA, TGA) and infrared spectroscopy (FTIR). The band gap energy (Eg) of each sample prepared was calculated from the UV-Vis absorption spectra. . The values of Eg obtained ranged from 3.5 to 3.2 eV. The best activity found for the methylene blue degradation was performed by the Na2ZrTi5O13 sol-gel pH 9, treated at 800oC (99%). We assumed that the photocatalytic activity is favored when the structure was already formed. Lead photocatalysed reactions using Na2ZrTi5O13sol-gel pH 9, treated at 600 oC showed a higher eficiency (98%) than that obtained by TiO2 (degussa) (85%)
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/10/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.486-487.57.pdf
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