The present study
demonstrates the hydrothermal synthesis of SnO2 quantum
dots (QDs) doped with different concentrations (2,
4 wt %) of magnesium (Mg) and a fixed amount of chitosan (CS). The
obtained samples were investigated through a number of characterizations
for optical analysis, elemental composition, crystal structure, functional
group presence, interlayer spacing, and surface morphology. The XRD
spectrum revealed the tetragonal structure of SnO2 with
no significant variations occurring upon the addition of CS and Mg.
The crystallite size of QDs was reduced by incorporation of dopants.
The optical absorption spectra revealed a red shift, assigned to the
reduction of the band gap energy upon doping. TEM analysis proved
that the few nanorod-like structures of CS overlapped with SnO2 QDs, and agglomeration was observed upon Mg doping. The incorporation
of dopants little enhanced the d-spacing of SnO2 QDs. Moreover, the synthesized nanocatalyst was utilized
to calculate the degradation percentage of methylene blue (MB) dye.
Afterward, a comparative analysis of catalytic activity, photocatalytic
activity, and sonophotocatalytic activity was carried out. Notably,
4% Mg/CS-doped QDs showed maximum sonophotocatalytic degradation of
MB in basic medium compared to other activities. Lastly, the prepared
nanocatalyst was found to be efficient for dye degradation in any
environment and inexpensive.