Nanoporous metals processed by dealloying and their applications

Porous metals and alloys have many important characteristics such as light weight, high surface area, good electrical conductivity, and enhanced surface plasmonics. They have found many applications in chemical and biomedical engineering fields. This review deals with various dealloying techniques for making nanoporous metals, alloys, and composite materials. Typical dealloying processes and their recent development are introduced. The dealloying techniques include chemical etching, electrochemical leaching, high temperature element removal, thermic reduction, Galvanic replacement, template approach, physical vacuum processing, magnetic field induced processing, plasma reaction etc. Although various noble porous metals such as Pt, Pd, Au, and Ru were extensively studied earlier for applications in catalysis and energy storage/conversions, other porous metallic alloys are under investigations for the removal of pollutants, energy absorbing, filtration of metal ions, organic dyes, and microbial organisms. Advances in processing nanoporous particles, nanosheets, and porous fibers will be discussed. The applications of recently developed nanoporous metals are presented as well