Nanoporous Metal Structures and Their Properties

Nanoporous metals are characterised by an interconnected network of ligaments and pores at the nanometre scale, arising principally from selective removal of one component from an alloy. This architecture endows such materials with an exceptionally high specific surface area, tunable mechanical compliance and unique transport pathways for electrons, ions and molecules. Fabrication routes include electrochemical and liquid-metal dealloying, vapour-phase dealloying and molten salt dealloying, each offering control over pore size, ligament thickness and overall morphology. Mechanical properties range from high strength and stiffness to remarkable ductility when embedded in polymer matrices, enabling interpenetrating-phase nanocomposites with tailored elastic behaviour. Surface-driven phenomena such as diffusion-mediated coarsening dictate long-term stability, while high surface energy sites confer excellent catalytic and electrocatalytic activity. The combination of porosity, conductivity and biocompatibility has spurred applications in energy conversion, sensing, filtration, actuation and biomedical implants. Advances in in situ characterisation and multiscale modelling have deepened understanding of formation mechanisms, coarsening kinetics and the relationship between topology and functional performance, paving the way for next-generation porous metal architectures with optimised properties for global technological challenges.

Research from Nature Portfolio

Recent studies have demonstrated vapour-phase dealloying as a green, universally applicable route to three-dimensional bicontinuous nanoporosity. By exploiting differences in vapour pressure, a broad range of alloys can be converted into nanoporous structures with fully recoverable leached elements and tunable pore dimensions, offering an environmentally benign alternative to conventional etching. High-temperature liquid-metal dealloying has yielded ultrafine nanoporous intermetallic catalysts, where chemical ordering during pore formation reduces surface diffusivity, suppresses coarsening and produces characteristic lengths below previous limits. The resultant Co7Mo6 and Fe7Mo6 catalysts show exceptional activity and durability for electrochemical hydrogen evolution. In situ synchrotron X-ray nano-tomography of molten salt dealloying has elucidated the rate-controlling steps of long-range diffusion, surface-diffusion-governed coarsening and interfacial instabilities, while revealing a nontoxic, tunable pathway to form corrosion-resistant porous metals relevant to energy systems and reactor materials.

Nanoporous Metal Structures and Their Properties publication trend

The graph below shows the total number of articles in nanoporous metal structures and their properties across all publications each year (not limited to Nature Index journals).

Technical terms

Dealloying: A selective corrosion or vapour-phase process that removes a less noble element from an alloy, leaving a porous metal network.

Bicontinuous structure: A morphology in which both solid and void phases form interpenetrating, continuous networks throughout the material.

Ligament: The solid strut or backbone in a nanoporous network that bridges neighbouring nodes of the structure.

Specific surface area: The total surface area per unit mass or volume of a porous material, critical for catalysis and sensing.

Surface diffusion: Mass transport along the surface of ligaments, governing pore coarsening and morphological evolution.

References

1. Three-dimensional bicontinuous nanoporous materials by vapor phase dealloying. Nature Communications (2018).
2. Ultrafine nanoporous intermetallic catalysts by high-temperature liquid metal dealloying for electrochemical hydrogen production. Nature Communications (2022).
3. Formation of three-dimensional bicontinuous structures via molten salt dealloying studied in real-time by in situ synchrotron X-ray nano-tomography. Nature Communications (2021).
4. Nanoporous Gold: From Structure Evolution to Functional Properties in Catalysis and Electrochemistry. Chemical Reviews (2023).
5. Preparation, Modification, Characterization, and Biosensing Application of Nanoporous Gold Using Electrochemical Techniques. Nanomaterials (2018).
6. Topology evolution during coarsening of nanoscale metal network structures. Physical Review Materials (2019).
7. Dealloying-based interpenetrating-phase nanocomposites matching the elastic behavior of human bone. Scientific Reports (2017).