Template-assistant synthesis of gold nanoparticles with mesoporous silica thin films

Abstract

Three kinds of amino-functional mesoporous silica thin films (AF-MSTFs) have been directly synthesised by the sol–gel dip coating. The Fourier transform infrared spectra show that the amino groups are introduced into the nanopores of AF-MSTFs successfully by co-condensation technology. The X-ray diffraction (XRD) and transmission electron microscope (TEM) characterisations find that the AF-MSTFs prepared by different surfactants have highly ordered mesostructures with different nanopore sizes and morphologies. By using AF-MSTFs as templates, associated with neutralisation reaction and hydrogen reduction, gold nanoparticles (GNPs) are formed well within the mesostructures with a narrow size distribution, which is verified by the observation of XRD, TEM and energy-dispersive X-ray analyses. Ultraviolet–visible spectra of the nanocomposites are additional evidence of the existence of GNPs. What is more, they imply that the size effect of GNPs and the structure variation of AF-MSTFs can modulate the optical properties of the nanocomposites.