Evaluation of the photodiscoloration efficiency of beta-Bi2O3 films deposited on different substrates by pneumatic spray pyrolysis
Por:
Gadhi T.A., Gómez-Velázquez L.S., Bizarro M., Hernández-Gordillo A., Tagliaferro A., Rodil S.E.
Publicada:
30 sep 2017
Resumen:
Immobilization of beta-beta i(2)O(3) over corning glass and sintered
silica discs was performed to evaluate a competing fixed support as an
alternative to slurry based photocatalytic systems. Pneumatic spray
pyrolysis technique was used to produce coatings of beta-beta i(2)O(3)
at 450 degrees C. Coated substrates were characterized using X-ray
diffraction (XRD) and UV-Vis diffused reflectance spectroscopy (DRS),
field emission scanning electron microscope (FESEM) and energy
dispersive X-ray spectrometry (EDS). The XRD analysis showed that the
obtained crystalline structure of the films is tetragonal beta-beta
i(2)O(3) for both glass and silica. DRS showed the broad absorbance
spectra of the films, correlated to beta-beta i(2)O(3) with an energy
band gap of 2.4 eV. FESEM showed that the morphology of the films was
different according to the substrate. In the case of corning glass,
random non-compact distribution of particles was observed while over
silica discs overlapped sheets of beta-beta i(2)O(3) were seen. This is
probably due to differences in the wetting and evaporation rate of the
sprayed droplets. During photodiscoloration of anionic indigo carmine
(IC) dye solution, the beta-beta i(2)O(3) coated silica was found more
effective than the coated glass, response associated to the larger
interaction between the dye molecules and catalysts assisted by the
roughness and porosity induced by the silica. Furthermore,
photocatalytic evaluation of coated silica in discoloration of other two
organic dyes: cationic rhodamine B (RhB) and anionic acid blue 113 (AB)
revealed that adsorption and interaction of the dye molecules with
coated films could vary due to the presence of different functional and
branched groups that overall affect the photocatalytic process, the
kinetic rate of discoloration and the TOC analysis. Finally, after the
assessment of stability of films and suitability of silica, it was
confirmed that silica discs are favorable as a photocatalyst support and
last long usage for photodiscoloration of organic dyes. (C) 2017
Elsevier B.V. All rights reserved.
Filiaciones:
Gadhi T.A.:
Politecn Torino, Dept Appl Sci & Technol, Turin, Italy
Department of Applied Science and Technology, Politecnico di Torino, Italy
Gómez-Velázquez L.S.:
Univ Nacl Autonoma Mexico, Inst Invest Mat, Circuito Exterior SN,Ciudad Univ, Mexico City 04510, DF, Mexico
Univ Nacl Autonoma Mexico, Posgrad Ciencia & Ingn Mat, Mexico City, DF, Mexico
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior SN, Ciudad Universitaria, CP 04510, Coyoacán, Cd. De México, Mexico
Posgrado en Ciencia e Ingeniería de Materiales, Universidad Nacional Autónoma de México, Mexico
Bizarro M.:
Univ Nacl Autonoma Mexico, Inst Invest Mat, Circuito Exterior SN,Ciudad Univ, Mexico City 04510, DF, Mexico
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior SN, Ciudad Universitaria, CP 04510, Coyoacán, Cd. De México, Mexico
Hernández-Gordillo A.:
Univ Nacl Autonoma Mexico, Inst Invest Mat, Circuito Exterior SN,Ciudad Univ, Mexico City 04510, DF, Mexico
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior SN, Ciudad Universitaria, CP 04510, Coyoacán, Cd. De México, Mexico
Tagliaferro A.:
Politecn Torino, Dept Appl Sci & Technol, Turin, Italy
Department of Applied Science and Technology, Politecnico di Torino, Italy
Rodil S.E.:
Univ Nacl Autonoma Mexico, Inst Invest Mat, Circuito Exterior SN,Ciudad Univ, Mexico City 04510, DF, Mexico
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Circuito Exterior SN, Ciudad Universitaria, CP 04510, Coyoacán, Cd. De México, Mexico
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