Gas-sensitive nanocomposites, based on silicon dioxide-metal oxide systems, were obtained via self-assembly using the sol-gel method. Surface morphology diagnostics of nanomaterials, synthesized from sol solutions in a precursor medium based on tetraethoxysilane, were made using atomic force microscopy. The main evolution stages of nanocomposites based on two-component systems were determined. Specific surface area measurements of nanocomposites were made using a Sorbi analytical instrument by the thermal desorption method. A method for increasing the specific surface area and gas-sensitivity of nanomaterials by modifying them using fullerenols is suggested.