Atmospheric Pressure Plasma Deposition of Hybrid Nanocomposite Coatings Containing TiO₂ and Carbon-Based Nanomaterials

Among the different applications of TiO2, its use for the photocatalytic abatement of organic pollutants has been demonstrated particularly relevant. However, the wide band gap (3.2 eV), which requires UV irradiation for activation, and the fast electron-hole recombination rate of this n-type semiconductor limit its photocatalytic performance. A strategy to overcome these limitations relies on the realization of a nanocomposite that combines TiO2 nanoparticles with carbon-based nanomaterials, such as rGO (reduced graphene oxide) and fullerene (C-60). On the other hand, the design and realization of coatings formed of such TiO2-based nanocomposite coatings are essential to make them suitable for their technological applications, including those in the environmental field. In this work, aerosol-assisted atmospheric pressure plasma deposition of nanocomposite coatings containing both TiO2 nanoparticles and carbon-based nanomaterials, as rGO or C-60, in a siloxane matrix is reported. The chemical composition and morphology of the deposited films were investigated for the different types of prepared nanocomposites by means of FT-IR, FEG-SEM, and TEM analyses. The photocatalytic activity of the nanocomposite coatings was evaluated through monitoring the photodegradation of methylene blue (MB) as a model organic pollutant. Results demonstrate that the nanocomposite coatings embedding rGO or C-60 show enhanced photocatalytic performance with respect to the TiO2 counterpart. In particular, TiO2/C-60 nanocomposites allow to achieve 85% MB degradation upon 180 min of UV irradiation.