Room temperature Phytosynthesis of Ag/Co bimetallic nanoparticles using aqueous leaf extract of Canna indica

Continuous quest for safe environment has led to 'green' approach of synthesizing nanoparticles. The method is easy, eco-friendly and cost-effective. Locally sourced medicinal plant Canna indica was used as capping/stabilizing agent instead of toxic chemicals. Secondary metabolites in the plant extract acted as reducing agents. Optical measurements were carried out using Uv-vis spectrophotometer and photoluminescence (PL). Formation of core-shell was detected in the TEM micrograph, which was supported by two peaks observed in surface plasmon resonance shown in the Uv-vis spectra. FT-IR spectrophotometric analysis indicated the presence of some specific functional groups in the phytochemicals which were adsorbed on the surface of nanoparticles. This analysis depicted the presence of hydroxyl group (O-H stretching) with a broad strong peak at 3360 cm^-1, C-H stretching at 2938 cm^-1, C=C stretching at 1659 cm^-1, C=N stretching at 1557 cm^-1 and C-O deformation at 1065 cm^-1. Crystalline phase of the nanoparticles was determined using X-ray diffraction (XRD). The plant-mediated green synthesized silver/cobalt nanoparticles are potential optical materials as a result of their broad absorption band and emission.