Exploring the functionalization ratio of mesoporous silica glass with imidazolium entities on the synthesis of supported gold nanoparticles

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)This study describes the surface modification of porous Vycor glass (R) (PVG (R)) 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 (R)) 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 AuCl4- throughout the monolithic PVG (R) 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 AuCl4- 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 (R) acts as a nanoreactor where the particles are formed in the confined space.153Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP