Structural Engineering of Au─Ag Heterometallic Nanoparticles Using Multidentate Polyoxometalate Ligands

Area of Science:

• Nanotechnology
• Materials Science
• Catalysis

Background:

• Precise structural control of heterometallic nanoparticles is challenging but crucial for advanced applications.
• Polyoxometalates (POMs) are versatile inorganic ligands with potential in nanomaterial synthesis.

Purpose of the Study:

• To develop a facile co-reduction strategy for synthesizing gold-silver (Au-Ag) heterometallic nanoparticles.
• To achieve controlled synthesis of either random alloy or core-shell Au-Ag nanoparticles using POM stabilizers.
• To evaluate the catalytic performance of the synthesized Au-Ag nanoparticles.

Main Methods:

• Co-reduction of gold and silver precursors stabilized by multidentate polyoxometalates.
• Tuning the Au:Ag precursor ratio to control nanoparticle morphology (alloy vs. core-shell).
• Immobilization of Au-Ag core-shell nanoparticles on carbon supports.

Main Results:

• Preferential formation of core-shell Au-Ag nanoparticles under co-reduction conditions.
• Selective synthesis of random alloy or core-shell structures by adjusting precursor ratios.
• Immobilized core-shell nanoparticles exhibited superior catalytic activity and selectivity in 4-nitrophenol hydrogenation and electrochemical CO2 reduction compared to analogues.

Conclusions:

• Polyoxometalate ligands effectively direct the growth and stabilize the structure of heterometallic nanoparticles.
• The developed strategy offers versatility in engineering nanoparticle structures for enhanced catalytic applications.
• This work opens new avenues for designing advanced catalysts and functional nanomaterials.