Nanoporous Dealloyed Metal Materials Processing and Applications─A Review

Abstract

The development of porous metal materials with pore geometries and sizes at the nanoscale offers promising opportunities for the development of smart responsive interfaces for separation and catalytic applications and as building blocks for complex composite materials. Dealloying is an innovative technique based on selective removal of a sacrificial metal from a metal alloy to engineer surface textures and pores across significant thicknesses. Dealloyed structures may be processed over large scales and for a range of source alloys, offering unprecedented manufacturing opportunities. This review presents the operations and challenges of dealloying routes and discusses avenues for process optimizations and improvements, aiming at the development of scalable nanoporous materials. The potential of dealloyed materials for catalytic and sensing applications is expanded and benchmarked against reference materials. Future prospects and applications of dealloyed materials toward surface reactivity control and pore architecture development are highlighted.

Nanoporous oxide electrodes for energy conversion and storage devices

“…6a, dealloying can be achieved through chemical etching, 3,[181][182][183][184][185][186] electrochemical processing, 181,[187][188][189][190] immersion in liquid metal, 181,[191][192][193] and solid-state stripping, 181,[194][195][196] as well as by vapor-thermal processing. 181,[197][198][199] The metal atoms in the primary alloy are changed into metallic ions by localized oxidation when nanoporous oxide materials are produced using dealloying procedures. These metallic ions are then released in the dealloyed result.…”

Porous Inorganic Nanomaterials: Their Evolution towards Hierarchical Porous Nanostructures

“…However, there are possible limitations considering material-template compatibility in this technique, and it entails post-synthesis template removal [13]. Copyright 2023 American Chemical Society [14].…”

“…On the other hand, in electrochemical dealloying, an electric field is applied to induce selective etching. The less noble atoms having lower corrosion potential will be removed first, resulting in the formation of porous structures [14].…”

“…Selective dissolution processes (i.e., dealloying [14,34,105]) emerge as an option to remove Cu from the near-surface regions of the glassy alloy while at the same time introducing surface roughness, which can create bioactive states for the optimal growth of bone tissue. Using an alkaline approach for the removal of Cu, Blanquer et al modified the surface of Ti 40 Zr 10 Cu 38 Pd 12 by polarizing the bulk samples in a 5 M NaOH solution at 25 • C. They obtained a porous structure layer of 200 nm thickness, which improved the corrosion resistance of the alloy.…”

“…Incorporating porosity into nanomaterials then presents exciting possibilities entailing further exploration of their physics and potential applications. Specifically focusing on porous inorganic nanomaterials and their hybrids, new materials have been developed, including porous metal nanostructures, porous oxide nanomaterials, porous carbon nanomaterials, nano-sized metal-organic frameworks (MOFs), and nano-zeolites [10,[13][14][15][16][17]. These offer increased surface areas, enhancing mass transport and binding capacities, facilitating, for example, an efficient interaction between immobilized molecules and target species.…”