Facile in situ preparation of noble metal nanoparticles supported on silica

Highly-dispersed noble metal nanoparticles (Au, Ag, Pd and Pt) supported on silica have been successfully prepared via reaction between modified silica and metal precursors in aqueous solutions, and the modified silica was synthesised through a sol-gel process of tetraethyl orthosilicate and 3-glycidoxypropyltrimethoxysilane (GPTMS) with aqueous ammonia as condensation catalyst. The transmission electron microscopy and X-ray diffraction results show that the noble metal particles are at nanoscale with good uniformity, and the diol species derived from 3-glycidoxypropyl groups of GPTMS are confirmed to serve as the reductants for metal precursors by solid state nuclear magnetic resonance spectra. The combination of noble metal nanoparticles and organic groups retained on silica would make the materials possess some special properties.