Titanium dioxide (TiO2) and silver/titanium dioxide (Ag/TiO2) thin films with self-cleaning properties

Ana Flávia R. Silva1, Nelcy D. S. Mohallem2, Marcelo M. Viana2*

1Chemical Engineering Department, Polytechnic Institute, Pontifical Catholic University of Minas Gerais, Dom José Gaspar Avenue, 500, Belo Horizonte, 30535-901, Brazil

2Laboratory of Nanostructured Materials, Chemistry Department, Exact Sciences Institute, Federal University of Minas Gerais, Presidente Antônio Carlos Avenue, 6627, Belo Horizonte, 31270-901, Brazil

Adv. Mater. Lett., 2017, 8 (4), pp 444-448

DOI: 10.5185/amlett.2017.7093

Publication Date (Web): Mar 14, 2017

E-mail: marcelomachado@ufmg.br

Abstract


In this work, TiO2 and Ag/TiO2 thin films were synthesized on glass by combination of sol-gel method and dip-coating deposition technique. Thermal treatment in temperatures ranging from 100 °C to 500 °C was used to evaluate changes in structure, morphology and texture of these materials. Adherent and microcrack-free films were obtained. The structural and morphological evolution with temperature was studied by X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Average particle size and roughness were determined by atomic force microscopy (AFM). The films were tested for wettability by measuring the contact angle between a drop of distilled water and the material surface. Results of hydrophobic/hydrophilic tests using UV-C irradiation showed that the films change their hydrophobic character to hydrophilic reaching even the superhydrophilic character which indicates their potential application as self-cleaning coatings. 

Keywords

Thin films, titanium dioxide, silver, sol-gel, self-cleaning.

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