Size-controlled synthesis of silver particles VIA green chemistry

Abstract

Silver nanoparticles (AgNPs) were successfully synthesized using “green chemistry”. Tapioca has been used both as reducing agent and stabilizer. Tapioca after treated with an acidic and alkaline solution generated reducing species which is used to completely reduce silver ions and sufficiently stabilize the obtained silver nanoparticles. The average size, size distribution, morphology, and structure of the synthesized silver nanoparticles were characterized by Ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Strong surface plasmon resonance peaks were observed at about 400 nm and the synthesized silver nanoparticles were spherical with an average particle size of 15 ± 2.3 nm with a narrow particle size distribution. XRD analysis showed that the silver nanoparticles were face centered cubic (fcc) structure. The degradation of tapioca via an acidic and alkaline treatment was investigated by ATR FT-IR spectroscopy. The synthesized silver nanoparticles are stable in aqueous solution over a period of two months at room temperature. The antibacterial activities of the silver nanoparticles were tested against Staphylococcus aureus and Escherichia coli bacteria. A very low concentration of silver nanoparticles (2.5 ppm) was shown to be an effective bactericide.