Nickel oxide–silica and nickel–silica aerogel and xerogel nanocomposite materials

The sol-gel method was used to prepare nickel oxide–silica and nickel–silica nanocomposite materials and the corresponding silica matrices. Different drying conditions were used to obtain aerogel and xerogel materials. The samples were characterized by thermal analysis, x-ray diffraction, N₂–physisorption, transmission electron microscopy techniques, and infrared spectroscopy. Aerogel samples had a much higher surface area than the xerogel samples; moreover, different supercritical drying conditions gave rise to a different porous structure, which influenced the size and distribution of the nanoparticles in the matrix.