Kinetically Controlling Surface Atom Arrangements in Thermally Robust, Amorphous High-Entropy Alloy Nanoparticles by...

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• High-entropy nanoalloys offer tunable functional properties via controlled surface atom arrangements.
• Understanding nanoalloy formation mechanisms is crucial for engineering these properties.

Purpose of the Study:

• To investigate how solvent selection impacts carbon doping and nanoparticle characteristics during synthesis.
• To establish a method for controlling surface composition in high-entropy nanoalloys.

Main Methods:

• Utilized reactive, nanosecond-pulsed laser synthesis with the Cantor alloy (CrMnFeCoNi) as a model system.
• Varied solvent composition to influence carbon incorporation and nanoparticle formation.
• Analyzed nanoparticle morphology, structure, and composition, including carbon shell formation and distribution.

Main Results:

• Solvent selection led to supersaturated carbon incorporation, forming amorphous nanoparticles with distinct carbon shells.
• Carbon shells were thermally stable up to 350 °C.
• Proposed kinetically controlled formation mechanisms involving carbon doping, shell formation, and coalescence.
• Demonstrated that carbon shell thickness and surface composition affect element-specific dissolution under electrochemical conditions.

Conclusions:

• Solvent-driven surface-compositional control is achievable in amorphous high-entropy nanoalloys.
• Reactive pulsed laser synthesis offers a novel approach for tailoring surface atom arrangements via carbon incorporation.
• The findings enable precise engineering of nanoalloy properties for specific applications, particularly in electrochemistry.