Preparation and stabilization of gold nanoparticles formed by in situ reduction of aqueous chloroaurate ions within surface-modified mesoporous silica

A convenient method for the synthesis and simultaneous stabilization of gold nanoparticles in organo-functionalized MCM-41 is described. The silanol groups present on the surface of the mesoporous matrix reduce aqueous chloroaurate ions, resulting in the formation of gold nanoparticles, which are subsequently anchored to the host matrix via organic functionality. The method, in which propylamine-MCM-41 or propylthiol-MCM-41 is treated with a dilute aqueous solution of HAuCl₄ at ambient conditions, is quite simple and environmentally benign as there is no need to add any external reducing agent. The nano-Au-MCM-41 hybrid materials were characterized by XRD, UV-Vis, TEM, XPS, EDX and N₂ adsorption measurements.