Bismuth-oxide nanoparticles: study in a beam and as deposited

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Bismuth oxide (Bi₂O₃) exhibits high ionic conductivity, making it suitable for solid-oxide fuel cells (SOFCs).
• The high-temperature stability of the optimal δ-phase of Bi₂O₃ limits its direct application in SOFCs.
• Nanostructured Bi₂O₃ offers a potential solution for stabilizing desirable phases at lower temperatures.

Purpose of the Study:

• To investigate the fabrication of nanostructured Bi₂O₃ films.
• To develop a method for producing Bi₂O₃ nanoparticles with controlled composition in situ.
• To assess the feasibility of using these films for SOFC applications.

Main Methods:

• Reactive sputtering and vapor aggregation to create free Bi-oxide nanoparticles.
• In-situ synchrotron-based photoelectron spectroscopy (PES) for real-time nanoparticle composition analysis.
• Post-deposition characterization using PES, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron diffraction.

Main Results:

• Successfully produced nanostructured Bi₂O₃ films via deposition of in situ generated nanoparticles.
• Demonstrated control over nanoparticle composition, yielding either Bi-metal/Bi-oxide mixtures or pure Bi-oxide.
• Characterization confirmed the chemical composition, grain dimensions, and crystal structure of the deposited films.

Conclusions:

• The developed method enables the fabrication of nanostructured Bi₂O₃ films with tunable properties.
• The films were found to exist in multiple Bi₂O₃ polymorphs.
• This approach shows promise for creating advanced materials for solid-oxide fuel cells.