Abstract:
Earth–abundant transition metal chalcogenide materials are of great research interest for
energy production and environmental remediation, as they exhibit better photocatalytic activity due
to their suitable electronic and optical properties. This study focuses on the photocatalytic activity
of flower-like SnS2 nanoparticles (composed of nanosheet subunits) embedded in TiO2 synthesized
by a facile hydrothermal method. The materials were characterized using different techniques, and
their photocatalytic activity was assessed for hydrogen evolution reaction and the degradation of
methylene blue. Among the catalysts studied, 10 wt. % of SnS2
loaded TiO2 nanocomposite shows
an optimum hydrogen evolution rate of 195.55 µmolg−1
, whereas 15 wt. % loading of SnS2 on TiO2
exhibits better performance against the degradation of methylene blue (MB) with the rate constant of
4.415 × 10−4
s
−1 under solar simulated irradiation. The improved performance of these materials
can be attributed to the effective photo-induced charge transfer and reduced recombination, which
make these nanocomposite materials promising candidates for the development of high-performance
next-generation photocatalyst materials. Further, scavenging experiments were carried out to confirm
the reactive oxygen species (ROS) involved in the photocatalytic degradation. It can be observed
that there was a 78% reduction in the rate of degradation when IPA was used as the scavenger,
whereas around 95% reduction was attained while N2 was used as the scavenger. Notably, very
low degradation (<5%) was attained when the dye alone was directly under solar irradiation. These
results further validate that the •OH radical and the superoxide radicals can be acknowledged for
the degradation mechanism of MB, and the enhancement of degradation efficiency may be due to the
combined effect of in situ dye sensitization during the catalysis and the impregnation of low bandgap
materials on TiO2
