Soft route for monodisperse gold nanoparticles confined within SH-functionalized walls of mesoporous silica†

In this paper, we report a soft route leading to small gold nanoparticles confined within the framework of 2D-hexagonal mesoporous SH-functionalised silicas. For that purpose, a hydrophilic bis-silylated precursor containing a disulfide unit was prepared. Framework-functionalised materials were obtained in one step by the ‘‘direct synthesis’’ method which consists of a co-hydrolysis and polycondensation of a bridged organosilica precursor with tetraethylorthosilicate (TEOS) in the presence of a non-ionic triblock co-polymer (P123) as structure-directing agent. Reduction of SS groups leads quantitatively to SH functional groups within the framework of 2D hexagonal mesoporous silicas. All these materials have been characterised by TEM, C and Si NMR experiments, nitrogen gas adsorption, powder XRD and elemental analysis. The subsequent growth of monodisperse gold nanoparticles of small size ( 2 nm) within the walls of mesoporous materials was studied and is discussed.