Remnant Copper Cation-Assisted Atom Mixing in Multicomponent Nanoparticles.

Area of Science:

• Materials Science
• Nanotechnology
• Catalysis

Background:

• Nanostructured high-/medium-entropy compounds are crucial for energy conversion but face challenges in forming stable single-phase structures due to complex thermodynamics.
• Cation exchange reactions (CERs) using copper sulfide templates are common for synthesizing multicomponent heteronanoparticles.
• Complete removal of copper cations during CERs limits further compositional tuning of the resulting nanocrystals.

Purpose of the Study:

• To develop a synthetic strategy for fabricating diverse, stable single-phase nanostructured compounds.
• To overcome the limitation of complete copper cation removal in traditional CERs.
• To enable subsequent compositional variations in heteronanoparticles for enhanced properties.

Main Methods:

• Partially suppressing anion sublattice transformation during CERs to retain copper cations.
• Utilizing Janus Cu2-xS-M2S (M = Ag, Au) nanocrystals as templates.
• Performing subsequent CERs on remnant copper cations to introduce additional elements.

Main Results:

• Successfully retained a portion of copper cations within silver sulfide and gold sulfide phases.
• Synthesized Janus Cu1.81S-M2S (M = Ag, Au) nanocrystals with residual copper.
• Enabled the construction of Janus Cu1.81S-AgAuS via subsequent CERs, preserving the heterointerface.
• Demonstrated a method to fabricate CER-driven heterostructures with diversified compositions.

Conclusions:

• The developed synthetic strategy allows for the creation of novel heterostructures with tunable compositions.
• Retaining residual copper cations is key to enabling sequential CERs for complex material synthesis.
• The resulting diversified heterostructures exhibit unique optical and catalytic properties, advancing energy conversion technologies.