Formation of Au−Ag Core−Shell Nanostructures in Silica Matrix by Sequential Ion Implantation

Abstract

Formation of Au core−Ag shell bimetallic nanoparticles in silica matrix is demonstrated through sequential implantation of Ag and Au ions and subsequent thermal annealing. Formation of core−shell structures is verified through optical absorption spectroscopy, high-resolution transmission electron microscopy, electron energy loss spectroscopy, and simulated optical extinction spectra. A mechanism for the formation of such unusual structures in ion-implanted silica is proposed. By controlling the implantation energy of the two ions properly and keeping the implantation sequence Ag first and then Au, it is possible to create Au core−Ag shell nanoparticles in the silica matrix with homogeneous distribution.

A critical review of nanohybrids: synthesis, applications and environmental implications

“…Wet chemical processes involving reduction or thermal decomposition of metal salts are the most used synthesis techniques. [96] Wide variations of wet chemical processes include: polyol methods, [97] photochemical deposition, [98] electroless plating, [99] solvothermal, [100] hydrothermal, [101] sol-gel, [39] ion-implantation, [102] epitaxial growth, [103] etc. Vapour-gas phase processes, such as flame aerosol [104] and plasma-assisted deposition [105] are also commonly used.…”

“…[107] Templatebased growth processes can be used to obtain hollow spherical, [108] porous [109] or tubular [110] structures. Matrix bound methods, however, utilise inorganic silica, the oil-water interface, and polymer or block-co-polymer matrices, where co-precipitation, [111] ion implantation, [102] emulsification [112] and reverse micellisation [113] processes grow NHs. Core-shell metallic layers sometimes include inorganic [114] or organic [115] linkers or spacers between them.…”

Synthesis and Optical Properties of Cu Core/Ti-Related Shell Nanoparticles in Silica Sequentially Implanted With Ti and Cu Ions

“…One of the most promising techniques to fabricate the glass-based nanocomposites containing metal NPs is ion implantation, which allows the realization of high metal-filling factor and the control of depth distribution of NPs in the substrate to a certain degree [8][9][10]. Besides, ion implantation by the combination of two different metal ions into dielectrics could also provide an effective route to fabricate NPs in different structures, i.e., mixture of monometallic NPs, bimetallic alloy NPs, and core-shell structures, all of which can produce quite distinctive optical responses [11].…”

Ion irradiation synthesis of Ag–Au bimetallic nanospheroids in SiO2 glass substrate with tunable surface plasmon resonance frequency

“…Purely chemical synthetic routes such as innovative colloidal self-assembly, [18][19][20]24,26 lithography methods such as electron beam lithography 28 and nanosphere lithography, 27,29 thermal deposition, 25 laser irradiation, 30 ion implantation and consequent annealing, 31,32 and ion irradiation and subsequent annealing [33][34][35] have been developed for manufacturing high efficiency platforms for the LSPR-based sensors. Nowadays, colloidal chemistry can produce a myriad of metal NPs in solutions with a variety of morphologies from sphere to complex core-shell, with very good control of the size distribution; [17][18][19][20][21][22][23] this control over the size, composition, and morphology of the NPs in a system can produce dramatically different absorption features in the visible or near-infrared spectrum.…”