In this study, a novel, green, and economical approach was applied for
the preparation of silver nanoparticles on the magnetic silica using the leaf extract
of Origanum vulgare plant. The prepared catalyst was characterized by using
transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and
Fourier transform infrared spectroscopy (FT-IR) and developed as a solid catalyst
for the reduction of p-nitrophenol (4-NP), methyl orange (MO) and methylene
blue (MB) in the presence of NaBH4 as a reductant reagent. The obtained kinetic
data for the reduction of MO, MB and 4-NP were fitted to first-order rate equations
and the calculated rate constants for the reduction of MO, MB, and 4-NP were as
follows -0.0489, -0.054, and -0.012 s respectively. Also, these nanoparticles
exhibit excellent reusability without significant loss of activity and negligible
deactivation has been observed after at least 10 cycles of reaction.