Preparation and characteristics of NiO-coated nano-fibriform silica

NiO-coated nano-fibriform silica (NFS) was prepared by an excessive soakage method and was characterized using transmission electron microscopy, X-ray diffraction, and physical N2 adsorption techniques under different conditions. The results demonstrate that the coated NiO is of a cubic crystal form. The best preparation conditions are incubation in a water bath at 95 °C for 2 h and drying at 45 °C for 17 h, which lead to a higher NFS utilization ratio and thus lower cost, and a well-distributed NiO coating on the carrier NFS. Nitrogen adsorption isotherms for NiO-coated NFS are similar to a type IV curve, with a specific surface area of 292.7 m2/g, adsorptive capacity of 379.2 cm3/g, and pore volume of 0.59 cm3/g. The average pore diameter of NiO-coated NFS is 8.01 nm, but most pore diameters are in the range 2.1-3.9 nm. Comparison of NiO-coated NFS and NiO(Ni)-coated sol-gel silica as catalysts reveals that NiO-coated NFS may be an effective catalyst and that NFS may be a good catalyst carrier.