Journal of Sol-Gel Science and Technology

, Volume 89, Issue 2, pp 380–391 | Cite as

A systematic study of multifunctional xTiO2/(100 − x)SiO2 thin films prepared by sol–gel process

  • Magnum Augusto Moraes Lopes de Jesus
  • Gustavo Henrique de Magalhães Gomes
  • André Santarosa Ferlauto
  • Luciana Moreira Seara
  • Angela de Mello Ferreira
  • Nelcy Della Santina MohallemEmail author
Original Paper: Functional coatings, thin films and membranes (including deposition techniques)


It is known that TiO2/SiO2 nanocomposite thin films have several properties improved when compared with the TiO2 or SiO2 pure thin films. In this work, a systematic study of xTiO2/(100 − x)SiO2 films (x = 0, 20, 40, 60, 80, and 100%) with different numbers of layers (1–5), i.e., different thicknesses, prepared by sol–gel process using dip-coating deposition was made. The films were thermally treated and characterized by UV–Vis spectroscopy and ellipsometry to evaluate the optical properties and thicknesses. Transmittance of the films were discussed by means of the interference fringes and refractive index modulation as a TiO2/SiO2 ratio function. The values of refractive index, extinction coefficient, and band gap obtained from ellipsometric analyses were related to the changes in UV–Vis spectra. The construction of the xTiO2/(100 − x)SiO2 structural models for a precise ellipsometric analyses were based on a comprehension of theoretical models. The glass substrate and SiO2 film were modeled by Cauchy; TiO2 film by Tauc–Lorentz and TiO2/SiO2 by Bruggeman theories. A graded refractive index function was necessary to fit the thicker films with low mean square error (MSE). Moreover, the refractive index values permitted the calculation of total porosity of the films, using Lorentz–Lorentz equation. Atomic force microcopy images showed clearly the effect of SiO2 addition on TiO2, reducing the particle size and root mean square roughness (from 1.4 to 0.3 nm). The lowest roughness of TiO2/SiO2 films was correlated with their enhanced hardness. All TiO2/SiO2 films showed a persistent super hydrophilicity that makes them suitable for applications in environmental and energy fields.

A systematic study of xTiO2/(100 − x)SiO2 films (x = 0, 20, 40, 60, 80, and 100%) with different numbers of layers (1–5) prepared by sol–gel process using dip-coating deposition was made. The effect of mixing SiO2 with TiO2, reducing the particle size and RMS roughness (from 1.4 to 0.3 nm) was correlated with their enhanced hardness and super hydrophilicity that makes them suitable for applications in environmental and energy fields


  • Systematic study of TiO2/SiO2 thin films as a function of thickness and composition.

  • Structure, morphology, mechanical, and optical properties understandings.

  • Cauchy, Tauc–Lorentz, and Bruggeman models were used for interpreting optical properties.

  • The films have presented superhydrophilic surfaces.

  • Those properties make the films promising for applications in environmental and energy fields.


TiO2/SiO2 thin films Sol–gel process Ellipsometry UV–Vis spectroscopy Atomic force microscopy Nanoindentation 



We would like to thank UFMG-Microscopy Center for the images and FAPEMIG, CNPq, and CAPES for financial support

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Supplementary material

10971_2018_4867_MOESM1_ESM.docx (203 kb)
Supplementary Information


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2018

Authors and Affiliations

  • Magnum Augusto Moraes Lopes de Jesus
    • 1
  • Gustavo Henrique de Magalhães Gomes
    • 1
  • André Santarosa Ferlauto
    • 2
  • Luciana Moreira Seara
    • 3
  • Angela de Mello Ferreira
    • 4
  • Nelcy Della Santina Mohallem
    • 1
    Email author
  1. 1.Chemistry Department, Universidade Federal de Minas GeraisICExBelo HorizonteBrazil
  2. 2.Centro de Engenharia, Modelagem e Ciências Sociais AplicadasUniversidade Federal do ABCSão PauloBrazil
  3. 3.Centro de Microsopia da UFMGBelo HorizonteBrazil
  4. 4.Chemistry DepartmentCentro Federal de Educação Tecnológica de Minas GeraisBelo HorizonteBrazil

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