Semiconductor-based heterogeneous photocatalysis has been one of the most promising processes for
the treatment of contaminated water. Among the available catalysts, titanium dioxide (TiO2) presents
the best photocatalytic properties, being chemically and biologically inert, stable, non-toxic, cheap
and easy to produce. However, its energy bang gap lies in the ultraviolet (UV) range, which is
responsible for a reduced spectral activation, since UV radiation corresponds to only 5% of the solar
spectrum [1]. For this reason, one of the main purposes of the scientific community has been to
improve the photocatalytic performance of TiO2, namely through an adequate doping of this material,
or through the creation of nanocomposites, to enable photocatalysis occurrence by the incidence of
visible light. One alternative concerns the application of nanocomposites of TiO2 with graphene and
graphene oxide to photocatalytic processes [2].
In this work, nanocomposites of TiO2 with different weight concentrations of graphene and graphene
oxide (namely 0.5%, 1%, 1.5% and 3%) were synthetized by a one-step hydrothermal method and
characterized in terms of morphology, crystalline structure, vibrational modes and optical band gap.
The photocatalytic activity of these nanocomposites was then evaluated through the degradation of
methylene blue and ciprofloxacin solutions under UV and visible radiation. The results indicated that
the studied nanocomposites presented higher degradation rates of the methylene blue than the pure
TiO2, which increased with the content of graphene/graphene oxide. However, these composites
proved to be less suitable to degrade the ciprofloxacin solution than the pure TiO2 nanoparticles.Portuguese Foundation for Science and Technology (FCT) -
UID/FIS/04650/2013, PTDC/CTM-ENE/5387/2014 and SFRH/BD/98616/2013; Basque Government
Industry Department under the ELKARTEK Program.info:eu-repo/semantics/publishedVersio
