title: Preparation of gold nanoparticles on silica substrate by radio frequency sputtering.
abstract: Radio frequency sputtering of gold on amorphous silica substrates was used for the preparation of Au nanoparticles on SiO2. Deposition experiments were carried out in Ar plasmas under mild conditions (RF power = 5/10 W, total pressure = 0.38 mbar, substrate temperature < or = 210 degrees C), focusing in particular on the effect of sputtering time (5/30 min) and substrate temperature on gold nucleation and coalescence, with the aim of obtaining SiO2-supported Au nanoparticles characterized by precise structural and morphological features. To this aim, several analytical techniques were employed for a thorough characterization of the systems properties, including glancing incidence X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and UV-Vis absorption spectroscopy. In particular, the evolution of optical spectra, i.e., of the surface plasmon resonance peak, was used as a probe for the structural features and was related to the results obtained by other characterization techniques. Gold nanoclusters (phi approximately 4/10 nm) dispersed uniformly on silica matrices were obtained under soft conditions, with morphology ranging from island to cluster like. The obtained results make possible a careful modulation of substrate coverage and gold nanoparticle size.
authors.affiliation: ISTM-CNR and INSTM, Department of Chemical Sciences, Padova University-Via Marzolo, 1-35131 Padova, Italy.
authors.forename: Lidia
authors.initials: L
authors.lastname: Armelao
authors.forename: Davide
authors.initials: D
authors.lastname: Barreca
authors.forename: Alberto
authors.initials: A
authors.lastname: Gasparotto
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Pierangelo
authors.forename: Eugenio
authors.initials: E
authors.lastname: Tondello
authors.forename: Stefano
authors.initials: S
authors.lastname: Polizzi
mesh_terms: D006046:Gold / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: D006046:Gold; D012822:Silicon Dioxide