A Facile Route in Controlling the Optical Absorbance of Polyvinylpyrrolidone-Capped Silver Nanoparticles Via Chemical Reduction Technique

Abstract

Abstract This work presents the synthesis of silver nanoparticles (AgNPs) capped with polyvinylpyrrolidone (PVP) via a simple chemical reduction approach. A route in controlling the optical absorbance of the AgNPs by varying the concentration of silver precursors, as reflected by the shifts and broadening of the UV-vis spectra of the AgNPs is also highlighted. Dynamic Light Scattering results revealed the narrow and small hydrodynamic size for AgNPs synthesized at low precursor concentration, while multiple hydrodynamic size peaks were observed for AgNPs produced at high precursor concentration. Likewise, Fourier transform-infrared spectroscopy confirmed the successful capping of PVP on the AgNPs through the O and N atoms as potential binding sites. Transmission electron micrographs revealed the formation of spherical PVP-capped AgNPs, having no apparent aggregation observed. A closer inspection of the micrograph showed the subsequent formation of rod-like growth template of the AgNPs, that might lead to the formation of non-spherical silver nanostructures.