Magical oxygen: Tuning Cu&Ag nanoporous membrane into nanoporous (Cu&Ag)@Ag core-shell alloy

Metallic glasses are perfect materials for preparing nanostructures by dealloying, but the obtained nanostructures are commonly of porous structures. Through the combination of chemical dealloying and ultrasonic vibration, ultrathin Cu&Ag bimetallic nanoporous membranes (NPMs) have been prepared from a Zr₄₈Cu₃₆Ag₈Al₈ MG ribbon. Furthermore, by introducing oxygen into the Zr₄₈Cu₃₆Ag₈Al₈ MG ribbon to change the mechanism of the dealloying process, nanoporous (Cu&Ag)@Ag core-shell alloy was synthesized by the one-pot chemical dealloying of Zr–Cu–Ag–Al–O amorphous/crystalline composite, which provides a new way to prepare metallic core–shell nanostructures by a one-pot method. The introducing of oxygen can enable the dissolution and redeposition of Cu, and tunes the Cu&Ag NPM into the nanoporous (Cu&Ag)@Ag core-shell alloy. The nanoporous (Cu&Ag)@Ag core-shell alloy exhibits better and robust antibacterial activity against E. Coli DH5α due to its better oxidation resistance caused by the Ag skin. The present work provides important insights into the tuning of nanostructures through simple dealloying.