Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/72271
Type: Artigo de periódico
Title: The preparation and application of silica-zirconia xerogel as potentiometric sensor for chromium(VI)
Author: Alfaya, AAS
Gushikem, Y
Abstract: Xerogel of SiO2/ZrO2 with Zr in amounts of 17.4, 25.4, and 32.8 wt% were prepared by the sol-gel processing method. The oxide particles were homogeneously distributed in the xerogel and the Cr(VI) adsorption capacities were 5.2, 7.0, and 7.8 wt%, following the increasing order of the ZrO2 loading. The potentiometric response was better for samples with higher ZrO2 loading, and the plot of E vs -log a(Cr(VI)), where a is the activity, showed a linear correlation with an angular coefficent of 57.2 mV, very close to the 59 mV required for nernstian behavior. For the other two samples with lower metal oxide loadings, the angular coefficients were lower, showing a larger deviation from ideal behavior. The potentiometric selectivity constants, k(x,y)(pot), where x is the primary ion (Cr(VI) in the present case) and y is the interferent ion, were calculated. The following values of K-x,y(pot) were found for the different interferent ions: Cl-, 0.24; NO3-, 2 x 10(-3); HPO42-, 2 x 10(-4); SO42-, 3 x 10(-5); Cr3+, 6 x 10(-9). (C) 1999 Academic Press.
Subject: silica/zirconia xerogel
potentiometric sensor for chromium(VI)
sol-gel process
silica/zirconia/chromium(VI)
Country: EUA
Editor: Academic Press Inc
Rights: fechado
Identifier DOI: 10.1006/jcis.1998.5887
Date Issue: 1999
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

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