NOVELTY - A composition comprises an aerometal.    USE - As aerometal containing composition, where aerometal comprises nanowire, powder, film or three-dimensional body; which is useful for electrochemical device (all claimed) such as in lighting, electronics, light and thermal insulation at unusual wavelengths, and further in fuel cells, pH- and other types of sensors, catalysts, and in biotechnology.    ADVANTAGE - The composition comprising aerometal can be formed efficiently by utilizing metallothermic processes on two- and three-dimensional structures comprising both single and multiple elements. The aerometal has density of 1-500 mg/cm3, surface area of 200-2000 m2/g, and average pore size of 0.4-1000 nm; and is photoluminescent or electroluminescent. The composition comprising aerometal is obtained in the form of nanoporous silicon and other metal, metalloid, or metal-oxide containing nanowires, in form of three-dimensional scaffold, and resulting materials possess unusual photoluminescence properties. The process can also be applied to phase separated glasses and glass ceramics to form highly porous materials and structures and allows for formation of extruded and molded devices that have additional benefit of being more mechanically stable than presently available aero gels.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for method for producing the aerometal, involving: method (A): (a) forming an aerogel of a metal oxide or metallaloid oxide; (b) subjecting the aerogel to a metallothermic process; and (c) optionally, removing reaction by-products to give a pure aerometal; or method (B): (a1) providing an aerogel comprising a metal oxide or metalloid oxide; (b1) extracting oxygen from the aerogel by reacting a metallic gas with the substrate in a heated inert atmosphere to form a metal-oxygen complex, where the inert atmosphere is heated to a reaction temperature to facilitate the oxygen extraction; and (c1) removing the metal-oxygen complex to yield a nanostructured substrate with a density of less than 500 mg/cm3.