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ABSTRACT: A new phytochemical method for the synthesis of gold nanoparticles is reported. The essential oils extracted from the fresh leaves of Anacardium occidentale are used for the reduction of auric acid to Au nanoparticles (NPs). The formation and morphology of synthesized NPs are investigated with the help of UV-visible, TEM and FTIR spectroscopy. The NPs synthesized at room temperature are mono-dispersed and hexagonal in shape with an average size of 36nm while those prepared at higher temperature are composed of a mixture of anisotropic particles. The UV-visible absorption spectra of these anisotropic NPs show asymmetry in the longer wavelength side. The quantity of oil is an important criterion modulating the shape of NPs. Possible biochemical mechanism leading to the formation of NPs is studied using FTIR spectroscopy. The potential of synthesized Au NPs as catalyst is explored for the hydrogenation of p-nitro phenol to p-amino phenol at room temperature.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 06/2012; 97:306-10. · 2.10 Impact Factor
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ABSTRACT: A rapid, one pot and biogenic fabrication of Pd nanoparticles is reported. Pd nanoparticles of size below 5 nm size are synthesized using the dried leaf powder of Anacardium occidentale. Rapid reduction results in the formation of spherical particles. The nanoparticles are characterized by XRD, TEM, UV-visible and FTIR analysis. The absorption spectra have continua which are characteristic of Pd nanoparticles. The broad nature of the XRD pattern arising due to reflections from the (111), (200), (220), (311) and (222) planes indicate crystallinity of the nanoparticles with face centered cubic (fcc) structure. The morphology and shape of the nanoparticles are obtained by analyzing TEM images. Most of the nanoparticles are spherical with size in the range 2.5 and 4.5 nm. FTIR spectra of dried Pd nanoparticles, native and treated dried leaf powder have been analyzed to find out the biomolecule responsible for the reduction of Pd(2+) and capping of the palladium nanoparticles. The possible mechanism of formation of the nanoparticles is suggested.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 02/2012; 91:35-8. · 2.10 Impact Factor
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ABSTRACT: Present study reports a green chemistry approach for the biosynthesis of Au, Ag, Au-Ag alloy and Au core-Ag shell nanoparticles using the aqueous extract and dried powder of Anacardium occidentale leaf. The effects of quantity of extract/powder, temperature and pH on the formation of nanoparticles are studied. The nanoparticles are characterized using UV-vis and FTIR spectroscopies, XRD, HRTEM and SAED analyses. XRD studies show that the particles are crystalline in the cubic phase. The formation of Au core-Ag shell nanoparticles is evidenced by the dark core and light shell images in TEM and is supported by the appearance of two SPR bands in the UV-vis spectrum. FTIR spectra of the leaf powder before and after the bioreduction of nanoparticles are used to identify possible functional groups responsible for the reduction and capping of nanoparticles. Water soluble biomolecules like polyols and proteins are expected to bring about the bio-reduction.
Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 03/2011; 79(1):254-62. · 2.10 Impact Factor
