Magnetic Ni/SiO ₂ composite microcapsules prepared by one-pot synthesis

The Ni/SiO2 composite microcapsules were prepared by a one-pot synthesis via thermally decomposing Ni(acac)2·2H2O in 2-pyrrolidone in the presence of tetraethyloxysilane and 3-aminopropyltrimethoxysilane (APS). Transmission electron microscopy and powder X-ray diffraction were used to characterize the general morphology of the resultant capsules as well as the crystalline phases of the Ni nanocrystals incorporated. Ultraviolet photoelectron spectroscopy and ultraviolet photoionization mass spectroscopy were adopted to analyze the gaseous species released during the reaction to elucidate the mechanism behind the formation of the Ni/SiO2 composite microcapsules. Preliminary experiments were designed to show the catalytic ability of the resultant capsules which were collectable by applying an external magnetic field.