Development of light-harvesting properties and inhibition
of photogenerated
charge carrier recombination are of paramount significance in the
photocatalytic process. In the present work, we described the synthesis
of core–shell heterostructures, which are composed of titanium
oxide (TiO
2
) and cerium oxide (CeO
2
) deposited
on a reduced graphene oxide (rGO) surface as a conductive substrate.
Following the synthesis of ternary rGO-CeO
2
@TiO
2
and rGO-TiO
2
@CeO
2
nanostructures, their photocatalytic
activity was investigated toward the degradation of rhodamine B dye
as an organic pollutant under UV light irradiation. The obtained structures
were characterized with high-resolution transmission electron microscopy,
field-emission scanning electron microscopy, energy-dispersive X-ray
spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction,
Brunauer–Emmett–Teller, X-ray photoelectron spectroscopy
surface analysis, and UV–Vis spectroscopy. Various parameters
including pH, catalyst dosage, temperature, and contact time were
studied for photocatalysis optimization. Heterostructures showed considerable
advantages because of their high surface area and superior photocatalytic
performance. In contrast, rGO-CeO
2
@TiO
2
showed
the highest photocatalytic activity, which is attributed to the more
effective electron–hole separation and quick suppression of
charge recombination at core–shell phases. A biological assay
of the prepared heterostructure was performed to determine the cytotoxicity
against breast cancer cells (MCF-7) and demonstrated a very low survival
rate at 7.65% of cells at the 17.5 mg mL
–1
concentration
of applied photocatalyst.