Exploring the functionalization ratio of mesoporous silica glass with imidazolium entities on the synthesis of supported gold nanoparticles Nanostructured Materials 2012. Special Issue Editors: Juan Manuel Rojo, Vasileios Koutsos

摘要

This study describes the surface modification of porous Vycor glass ~? (PVG~?) with ionic species based on 1-methyl-imidazolium groups, and the posterior utilization of the functional porous substrate to synthesize supported gold nanoparticles (Au NPs). The functionalization degree (amount of imidazolium groups per gram of PVG ~?) was successfully controlled by the concentration of the imidazolium-based alkoxysilane in the reaction media. The ion-exchange properties of the functional groups allowed an effective and homogeneous upload of AuCl_4 ~- throughout the monolithic PVG~? structure, with subsequent conversion to Au NPs by thermal treatment at 823 K, which also eliminated the organic groups chemically bonded to the surface. The amount of adsorbed AuCl_4 ~- ions was shown to have influence on loading of the Au NPs while no size variation is observed, indicating that the porous environment of PVG~? acts as a nanoreactor where the particles are formed in the confined space.