Synthesis, characterization and optical properties of silver and gold nanowires embedded in mesoporous MCM-41

Abstract

Uniform nanowires of silver and gold inside the channels of MCM-41 were prepared by controlled reduction of their respective metal salts with sodium borohydride (NaBH 4 ). Presence of nanowires of silver and gold in MCM-41 were confirmed by high angle X-ray diffraction (XRD) data (peaks between 2θ = 30 − 60• ) and transmission electron microscopy (TEM) confirmed the diameter of the nanowires. Diameter of nanowires is found to be ∼ 2.8 nm which is coincident with channel diameter of MCM-41. Optical properties of these heterostructured materials Ag-MCM-41 and Au-MCM-41 reveals the presence of surface plasmon absorption peaks of silver and gold respectively, and the shift in the absorption bands are associated to agglomeration of clusters inside the channels. Room temperature photoluminescence spectra exhibits interesting optical properties as observed for direct band gap semiconductors. Non-linear optical properties (NLO) corresponding to second harmonic generation (SHG) values were also recorded for self supported films of these heterostructured materials. Enhanced optical non-linearity was found to be arising from a corresponding increase of local field near the surface plasmon resonance. Further enhancement in SHG was found with poling due to an induction of orientation order.

Oxidation of olefins using atmospheric oxygen atoms initiated by tert-butylhydroperoxide or hydrogen peroxide with silver nanoparticles deposited on MCM-41 as catalysts

“…E-mail: rluck@mtu.edu formation of Ag wires inside of mesoporous silica including MCM-41. [24][25][26][27] Interestingly, the adventitious formation of AgCl on the surface of recycled Ag nanoparticle catalyst permitted the use of H 2 O 2 as an initiator.…”

Theoretical studies on the electronic structures and spectra of single silicon-doped SWCNTs

“…Nano materials have been widely studied [1][2] since they have extraordinary magnetic [3] and optical properties [4]. The discovery of carbon nanotubes [5] is a milestone in the research of nano science and technology.…”