Abstract:
Developing an eco-friendly approach for metallic nanocatalyst synthesis is important in
nanoremediation research. The current study reports, a rapid, environmentally-friendly, and low cost
production of silver nanoparticles from silver nitrate using the aqueous extract of Thunbergia grandiflora
flowers and their use for the catalytic degradation of a hazardous Congo red dye. The UV-Visible spectral
analysis confirmed the formation of silver nanoparticles by its characteristic surface plasmon resonance
peak observed at 430 nm. SEM analysis resulted in the formation of spherical shaped nanoparticles. The
EDX spectrum displayed the presence of elemental silver at 3.1 keV. The XRD analysis showed a sharp peak
at 38.31° indicating the presence of (1 1 1) lattice plane. The FTIR analysis showed prominent peaks in the
flower extract corresponding to the specific functional groups which involved synthesis and stabilization of
nanoparticles. The DLS analysis revealed that the synthesized nanoparticles are less than 100 nm size. A
negative zeta potential of – 24.5 mV implied the negative surface charges of the nanoparticles. The
synthesized silver nanoparticles displayed excellent catalytic effectiveness in the reduction of carcinogenic
azo dye (Congo red) which is a highly toxic environmental organic pollutant. The nanoparticles show
excellent catalytic activities and follow pseudo-first-order kinetics. This finding may pave the way for the
development of new nanocatalysts for remediation of organics.
