Design nanoporous metal thin films via solid state interfacial dealloying

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Thin-film solid-state interfacial dealloying (thin-film SSID) is an emerging technique for fabricating nanoarchitectures.
• The resulting 3D bicontinuous nanostructures show promise for catalysis, sensing, and energy storage applications.

Purpose of the Study:

• To demonstrate thin-film SSID's capability in creating fine nanoporous structures (5-15 nm).
• To explore the use of multilayer thin-film designs for broader substrate compatibility.
• To investigate the phase evolution mechanisms in metal-agent dealloying.

Main Methods:

• Multiscale microscopy: X-ray and electron nano-tomography.
• Multimodal synchrotron diffraction and spectroscopy analysis.

Main Results:

• Thin-film SSID can produce very fine (5-15 nm) nanoporous structures, among the finest achieved by metal-agent dealloying.
• Multilayer designs enable nanoporous film fabrication on diverse substrates.
• Phase evolution in metal-agent dealloying is influenced by both enthalpy and entropy changes.

Conclusions:

• Thin-film SSID is a versatile technique for creating controllable 3D nanoarchitectures.
• Entropy contributions are crucial for understanding phase evolution in dealloying processes.
• This work advances the design principles for nanoarchitectural thin films and expands material selection possibilities.