Green synthesis of silver nanoparticles using polyalthia longifolia stem bark extract and its catalytic reduction of 4-Nitrophenol

Abstract

In this present study, green synthesis of silver nanoparticles (AgNPs) was synthesized from silver nitrate using the reducing agents of Polyalthia longifolia bark extract and applied the catalyst in the reduction/degradation of environmental polluted organic compound in the presence of NaBH4. Initially, the colourless reaction mixture was slowly changed to yellowish brown, UV-visible spectroscopy of surface plasmon resonance centre at 447 nm confirmed the formation of AgNPs. High resolution transmission electron microscopy (HRTEM) clearly identified the spherical shapes nanoparticles with diameters sizes 5-25 nm. This AgNPs has excellent catalyst in the catalytic reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) as compared to the reducing agent of NaBH4 (chemical) and plant extract (natural).