Polyaniline-sensitized SiO2/TiO2 photocatalysts for the degradation of phenol using visible light

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Vol. 425; p. 113696
• Main Authors: Acosta-Alejandro, J.A., López-González, R., Frías-Márquez, D.M., De La Rosa-Vázquez, J.M., Uribe-López, M.C., Gómez, R.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.03.2022
• Subjects: Conductive polymer; Core/shell; Photodegradation; Silicon dioxide; Titanium dioxide; Photodegradation; Core/shell; Conductive polymer; Titanium dioxide; Silicon dioxide
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/j.jphotochem.2021.113696

[Display omitted] •The modified Stöber method successfully control the morphology and size of the cores.•The etching on the surface of silicon oxide cores increase its porosity.•The surface porosity of cores enhances the formation of the TiO2 shell systems.•With the lowest content of the conductive polymer the photodegradation of phenol increases. In this research, the surface modification has been studied as alternative to improve the photocatalytic properties of the materials. The principal novelty of the core/shell synthesis was the in situ oxidation of the monomer aniline in polyaniline over the TiO2 surface, it gives an increase in the electron transport to enhance the photocatalytic activity of the SiO2/TiO2 system. Thus, the step by step synthesis allow us to modify the superficial porosity of the SiO2 cores for the further formation of the titanium dioxide shell, the resulting surface of the material was modified with different amounts of a conductive polymer polyaniline. The results indicate a successfully coverage by the titanium dioxide in the anatase phase (XRD), the extent of the coverage was confirmed by the FESEM and HRTEM images, it is clear the effect of the methodology on the porosity of the cores, with the highest porosity the more successfully covering, this also indicates an increased specific area creating more available sites for the reactive species formation for the photodegradation. The energy band gap of covered core/shell materials do not present significant modifications compared with pure anatase TiO2 indicating that the photoactivity of the materials occurs by the electron conduction by the π-polaron transitions of polyaniline deposited on the surface of titanium dioxide. The photodegradation results indicate the possibility use of the materials for the of aromatic compounds decompositions under visible irradiation.