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

The sol-gel method was used to prepare nickel oxide-silica and nickel-silic a nanocomposite materials and the corresponding silica matrices. Different drying conditions were used to obtain aerogel and xerogel materials. The sa mples were characterized by thermal analysis, x-ray diffraction, N-2-physis orption, transmission electron microscopy techniques, and infrared spectros copy. Aerogel samples had a much higher surface area than the xerogel sampl es; moreover, different supercritical drying conditions gave rise to a diff erent porous structure, which influenced the size and distribution of the n anoparticles in the matrix.