Nanoporous foam fabricated by dealloying AgAl thin film through supercritical fluid corrosion

摘要

In this research, nanoporous silver foams are fabricated through dealloying Ag _(35) Al _(65) (as atomic percentage, at%) thin films in supercritical (SC) carbon dioxide. The supercritical CO _(2) is mixed with either HCl, water or H _(2) C _(2) O _(4) aqueous solution as the solute in the reaction chamber. Due to the low tension of the supercritical fluid, under the best operating conditions, the surface area of the as-dealloyed Ag _(35) Al _(65) can reach 4.6 m ~(2) g ~(?1) , and the porosity volume fraction value can reach 74%, with a smallest average pore size of around 75 nm. In an optimum supercritical CO _(2) environment, a lower chemical concentration can be applied and it can take less time to form a uniform nanoporous structure.