Keywords : Gold

Plasmonic Resonance In Spray Deposited Au Nanoparticles Grown On TiO2 Thin Film

Promod Kumar; M. M. Ahmad

Advanced Materials Letters, 2015, Volume 6, Issue 7, Pages 628-632
DOI: 10.5185/amlett.2014.5745

Gold nanoclusters embedded in titania (TiO2) matrix were synthesized by thermal spray method followed by thermal annealing in an inert atmosphere. The effect of annealing temperature on the plasmonic response and optical properties of gold nanocluster in titanium dioxide matrices have been investigated by using UV-visible absorption spectroscopy. The surface plasmon resonance (SPR) at metal-dielectric interface for gold nanoparticles has been observed for as deposited samples at 561.8 nm which degrade as a function of post annealing temperature. Field emission scanning electron micrographs confirm the presence of spherical nanoparticles whose size increases with post annealing temperature. The plasmonic resonance of noble metals at nanoscale is fundamentally and technologically important for light trapping photovoltaic and other applications.

Growth, Characterization And I-V characteristics Of Tin Oxide Nanowires

Anima Johari; M.C. Bhatnagar;Vikas Rana

Advanced Materials Letters, 2012, Volume 3, Issue 6, Pages 515-518
DOI: 10.5185/amlett.2012.icnano.251

One-dimensional wire shaped tin oxide (SnO2) nanostructures have been synthesized by thermal evaporation method. The growth of SnO2 nanostructure was carried out on gold catalyst layer coated silicon substrate. X-ray diffraction (XRD) results reveals that synthesized SnO2 nanowires have polycrystalline nature with tetragonal rutile structure. SEM, TEM and EDX observation concludes that the uniform SnO2 nanowires (diameter ~ 40 nm and length ~ 50 μm) grow with vapor-liquid-solid (VLS) mechanism. I-V characteristics of single SnO2 nanowire show semiconducting behaviour. Due to structural and electrical properties of SnO2 nanowire, these nanowires would be a promising candidate for gas sensing applications.

pH Dependant Fungal Proteins In The ‘green’ Synthesis Of Gold Nanoparticles

Rashmi Sanghi; Preeti Verma

Advanced Materials Letters, 2010, Volume 1, Issue 3, Pages 193-199
DOI: 10.5185/amlett.2010.5124

An efficient, simple and environment friendly biosynthesis of gold nanoparticles (GNPs), mediated by fungal proteins of Coriolus versicolor is reported. By altering the reaction conditions, the intracellular synthesis of GNPs on the fungal mycelium, could be well tailored to produce extracellular GNPs in the aqueous medium. The reaction rate and the morphology of the particles were found to depend on parameters such as pH, incubation temperature and concentration of gold solution. The gold nanoparticles were characterized by UV–Vis, SEM and AFM techniques, demonstrating high stability of gold nanoparticles in aqueous media, via the protein layer. The size of the gold nanoparticles using AFM studies was found to be in the range 5–30 nm. These nanoparticles were found to be highly stable as even after prolonged storage for over 6 months they do not show aggregation. A plausible mechanism explaining the role of different possible proteins under different conditions, in the formation of gold nanoparticles has been investigated using FTIR. This study represents an important advancement in the use of fungal protein for the extracellular synthesis of functional gold nanoparticles by a green and mild technique in one pot.