Green Synthesis of Silver Nano-Particles by Use of Edible Oils.

Avoiding use of environmentally hazardous reducing agents and surfactants like sodium borohydride, hydrazine hydrate, alkyl amines and alkyl phosphines, the current article describes successful synthesis of silver nanoparticles via green synthesis by employing coconut, Indian gooseberry (amla), almond and mustard oils as capping as well as reducing agents. The presence of various fatty acids in such edible oils act as capping agents through their carboxylic acid functionality and control the growth of nanoparticles. A single step, simple synthetic method yielded silver nanoparticles which were characterized by UV-Visible, fluorescence spectroscopy, XRD, TEM and particle size analysis. As-prepared particles showed surface plasmon resonance (SPR) between 410 nm to 430 nm with narrow peak width indicating formation of homogeneous sized particles. XRD revealed formation of face cantered cubic crystal structure of silver. TEM analysis of the samples showed spherical morphology with particle size typically between 10-20 nm.

Nano-silver mediated polymerization of pyrrole: synthesis and gas sensing properties of polypyrrole (PPy)/Ag nano-composite.

Thermal polymerization of pyrrole was performed using silver nitrate as source of silver ions followed by its conversion to Polypyrrole (PPy)/Ag nano-comoposites without using any external oxidizing agent or solvent. The formation of PPy was monitored by UV-Visible absorption spectroscopy showing a band at approximately 464 nm. XRD measurement confirmed characteristic peaks for face centered cubic (fcc) silver and presence of PPy at 2 theta of approximately 23 degrees suggesting the formation of PPy/Ag nanocomposite. Transmission electron microscopy (TEM) images showed non-aggregated spherical Ag nano-particles of about 5-10 nm. PPy/Ag thick film acts as a NH3 sensor at 100 degrees C, a H2S sensor at 250 degrees C and CO2 sensor at 350 degrees C. The thick films showed capability to recognize various gases at different operating temperature.

Glycerol mediated low temperature synthesis of nickel nanoparticles by solution reduction method.

Phase pure Nickel nano-particles were synthesized by in-situ generation of nickel hydrazine hydrate complex (Ni-HH) followed by its decomposition in an alkaline glycerol medium. The synthesis can be performed in an open beaker with or without the use of surface protective reagents. By using the present method, Ni nano-particles can be prepared in large scale. The black nano-powders so-obtained were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infra-red (FTIR) spectroscopy and thermal analysis (TGA). XRD and SAED analysis revealed that the synthesized particles were pure crystalline nickel with FCC structure.