Structural analysis of PVP capped silver nanoparticles synthesized at room temperature for optical, electrical and gas sensing properties

An aqueous-phase method for the synthesis of polyvinylpyrrolidone (PVP) capped silver nanoparticles (AgNPs) at room temperature was developed, followed by wet chemical reduction method. The nanoparticles thus prepared were investigated for their optical properties, structural, thermal and electrical behavior using transmission electron microscopy (TEM), X-ray powder diffraction (XRD), UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR) thermogravimetric analysis (TGA) and current–voltage (I–V) characteristic respectively. The structural analysis showed that synthesized material is face-centered cubic (fcc) and monodispersed within the PVP matrix with an average size of 22 nm. The controlled size of the synthesized nanoparticles reveals that PVP played a critical role in controlling the radius and dispersibility of the nanoparticles. Electrical response showed a conductive and metallic nature. Ammonium gas sensing of the synthesized nanoparticles were investigated. It was found that the fabricated PVP capped AgNPs thin film showed the maximum sensitivity towards ammonia gas.