Facile and novel route for preparation of silica/silver heterogeneous composite particles with hollow structure

Silica/silver heterogeneous composite particles with hollow structure were successfully prepared by novel strategy including water-in-oil (W/O) emulsion and polyol process. First, 3-mercaptopropyltrimethoxysilane (MPTMS)-functionalized hollow silica particles were synthesized by adding tetraethyl orthosilicate (TEOS) and MPTMS successively into W/O emulsion. Second, these hollow particles were coated with silver nanoparticles through polyol process. After the preparation, a large number of quasi-spherical silver nanoparticles with a size of ∼50 nm in diameter were densely and uniformly formed at the surface of hollow silica particles. The resulting composite particles were characterized by the transmission electron microscopy (TEM), the field emission scanning electron microscopy (FE-SEM) including an energy-dispersive X-ray (EDX), and the X-ray diffraction (XRD) analysis. On the basis of the experimental results, the preparation steps for hollow silica supports and silver layers were discussed.