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Morphological characterization and photocatalytic efficiency measurements of pure silica transparent open‐cell sponges coated with TiO 2
Author(s) -
Löffler Frank B.,
Altermann Fabian J.,
Bucharsky Ethel C.,
Schell Karl G.,
Vera Maria L.,
Traid Hernan,
Dwojak Anabela,
Litter Marta I.
Publication year - 2020
Publication title -
international journal of applied ceramic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.4
H-Index - 57
eISSN - 1744-7402
pISSN - 1546-542X
DOI - 10.1111/ijac.13504
Subject(s) - photocatalysis , materials science , titanium dioxide , scanning electron microscope , chemical engineering , porosity , aqueous solution , sponge , reaction rate constant , nanotechnology , catalysis , composite material , kinetics , organic chemistry , chemistry , botany , physics , quantum mechanics , engineering , biology
Transparent glass sponges are a new class of materials that can potentially be used for effective light distribution in photocatalytic applications. In this work, transparent glass sponges are prepared by the polymer replica technique and coated with TiO 2 to obtain a highly efficient photocatalytic material. Necessary conditions for obtaining transparent open‐celled glass sponges are presented. The structure is characterized by employing light microscopy and scanning electron microscopy. In addition, µ‐computer tomography (µ‐CT) volume image analysis was performed that allows the calculation of geometrical parameters like pore size and specific surface area (SSA) of the structure, required for application of the new material. For photocatalytic application, the sponges have been coated with titanium dioxide (TiO 2 ) by immersion in a suspension of TiO 2 nanoparticles. The activity of the resulting coatings has been tested with the model reaction of transformation of Cr(VI) to Cr(III) in aqueous solutions in the presence of EDTA at pH 2. The reaction kinetics could be adjusted to a pseudo‐first order reaction and the obtained rate constants have been employed to evaluate the photocatalytic activity. The activity of the sponges has been compared with that of samples of glass plates coated with TiO 2 ; it has been found that the sponges exhibited a higher catalytic activity than the glass plates. The photocatalytic activity increased with the porosity of the sponges, and the optimum sample was determined based on its photocatalytic performance and its mechanical stability. The results are promissory for application in photoreactors for transformation of pollutants in water and air decontamination.