Facile route fabrication of nano-Ni core mesoporous-silica shell particles with high catalytic activity towards 4-nitrophenol reduction

A facile, environmentally friendly synthetic route was developed to prepare nano-Ni core mesoporous-silica shell particles. Ethylenediaminetetraacetic disodium salt (EDTA) was the chelating agent and thus controlled the nucleation rate of the nano-Ni core. In this work, EDTA was used to regulate the reduction rate of nickel acetate. Thereby, by varying the amount of EDTA utilized in reaction medium, the size of nano-Ni can be readily controlled in the range of 40-80 nm. The mesoporous silica shell was fabricated by the Stober method. The nano-Ni core mesoporous-silica shell particles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). UV spectrophotometry (UV/vis) was used to analyse the growth mechanism of the nano-Ni cores. The as-synthesized nano-Ni core mesoporous silica shell particles were found to show a good catalytic activity towards the reduction of 4-nitrophenol to 4-aminophenol in the presence of an excess amount of NaBH4. The magnetic properties, catalytic mechanism and the possibility of reusability were also investigated.