Design and preparation of a massive trimodal porous silver by the combinational process of Gasar and dealloying

Abstract

This study introduces a combined way of Gasar and dealloying process for fabricating massive three-level hierarchically porous silver (MTHPS). The key contributions of this research lie in improving the dimension of obtained hierarchical porous metals. The thickness of the de-alloyed precursor can be skillfully characterized by the inter-pore spacing l in Gasar porous metals utilizing Gasar process. By effectively adjusting the phase in as-cast Mg82.43Ag17.57 and the corrosion solution, the MTHPS samples with different morphologies are obtained. After dealloying the as-cast Gasar porous Mg82.43Ag17.57, hierarchical porous Ag which consists of lotus-type macropores (a diameter of 376 ± 86 μm), honeycomb submicron pores (a diameter of 360 ± 78 nm), and continuous ligament/channel structures (with pore diameters less than 56 ± 23.9 nm) were obtained. The Mg4Ag phase was observed in the T4-treated Gasar porous Mg82.43Ag17.57, which contributes to the formation of a novel tertiary porous structure. In addition, the catalytic performance of MTHPS for formaldehyde was evaluated in an alkaline environment, and the results showed that three-level porous silver with small pore size and well-continuous ligament/channel structured nanopores exhibited excellent electrocatalytic properties.