Preparation of nanoporous silver micro-particles through ultrasonic-assisted dealloying of Mg-Ag alloy ribbons

Abstract Nanoporous silver (NPS) micro-particles were prepared successfully by combining high-intensity ultrasonic irradiation (UI) and chemical dealloying process of rapidly solidified Mg-Ag precursors. The length scale of the ligaments in NPS is 100±30 nm, which is insensitive to the concentration of the hydrochloric acid (HCl) solution and the intensity of the UI. However, smaller NPS micro-particles with a size of 50±20 μm can be obtained by dealloying the precursor ribbons in a much more concentrated HCl solution under UI. It is supposed that the cavitation phenomena induced by UI treatment may play a key role in disaggregating the precursor ribbons into the present NPS micro-particles during dealloying.