Abstract: The highly ordered amino-functionalized mesoporous silica thin films (MTFs) have been directly synthesized by co-condensation of tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES) in the presence of P123 (EO20PO70EO20). Using the neutralization-reaction mechanism followed with a reduction procedure of hydrogen-ambience calcinations, the gold nanoparticles have been effectively introduced into the pore channels of amino-functionalized MTFs, and obtained the Au/SiO2 nanocomposite. The nanomaterials were characterized by XRD, TEM, and UV-vis. It was found that removing the surfactant by ethanol extraction can get well-ordered mesoporous structures compared with the calcinations; gold nanoparticles grow in a preferred orientation of (111) planes of the face-centered-cubic structure in the pore channels and crystallized nicely; the absorption spectrum of Au/SiO2 nanocomposite undergoes a red-shift as the reaction time increase. It is a quantum size effect of gold nanoparticles, and shows that the dipping time could regulate the dispersive property of Au/SiO2 nanocomposite.

Key words: Mesoporous silica thin film, Amino-functionalized, Gold nanoparticle, Absorption spectrum, Dispersive property