Structural characterization of FeCo alloy nanoparticles embedded in SBA-16 and their catalytic application for carbon nanotubes production

The formation of FeCo alloy nanoparticles embedded in a highly ordered 3D cubic mesoporous silica matrix (SBA-16) was thoroughly studied using several techniques. In particular, the selectivity of Extended X-ray absorption fine structure and X-ray absorption near-edge structure spectroscopy at both the Fe and Co K-edges allowed us to determine that before reduction treatment Fe and Co are present in a poorly crystalline environment, while after reduction treatment FeCo nanoparticles with the typical bcc structure are formed. FeCo alloy nanoparticles are used in several applications: biomedical (magnetic carriers for drug delivery and cell separation), magnetic (data storage) and catalytic. In this work, FeCo nanoparticles formed in situ in the SBA-16 matrix were used for the production of carbon nanotubes by catalytic chemical vapour deposition. Transmission electron microscopy indicates that good quality multi-walled carbon nanotubes are obtained.