Synthesis, Characterization of PVP Stabilized Silver Nanoparticles for Gas Sensing Applications

A new aqueous-phase method for the preparation of silver nanoparticles dispersed in acetone was successfully developed in this paper. The silver nanoparticles were obtained in aqueous by reduction of silver nitrate with \nsodium borohydrate as reducing agent and stabilized by Polyvinylpyrrolidone immediately. The PVP stabilized silver nanoparticles solution is bright yellow colored and are stable over a long period of time with no indication of aggregation. The solution shows strong visible light absorptions at 406 nm, characteristics of silver nanoparticles. Transmission electron microscopy of \nthe sample revealed well-defined non-agglomerated spherical particles of about 50 nm. In FT-IR spectrum strong absorption band of a carbonyl stretching group due to PVP indicates its presence on nanoparticle surface. \nThe particles sizes of nanoparticles can be controlled by reaction parameters such as time, temperature, and concentration of reagents and stabilizing agent. The very controlled size of the synthesized nanoparticles reveals that PVP played a critical role in controlling the radius and dispersibility of the nanoparticles. The silver nanoparticles show the maximum sensitivity with ammonium gas because it makes silver metal complexes so can be used as ammonia sensor. In future, LB thin film of silver nanoparticles may be fabricated for sensor applications.