Ag-Ga Bimetallic Nanostructures Ultrasonically Prepared from Silver-Liquid Gallium Core-Shell Systems Engineered for Catalytic Applications

Silver (Ag) nanoalloys play significant roles in several industrial applications. While still many sustainable frameworks can be explored for the synthesis and functional incorporations, the control of phase and structure at the nanoscale still is a major challenge for their practical implementation. In this study, liquid-phase gallium (Ga-(L)) nano-/microspheres were utilized for this purpose, investigating their function as reaction media and metallic alloying elements for the development of one-dimensional (1D) Ag-Ga nanoalloys from a silver fluoride precursor. Ultrasonic input at near room temperature was selected for the green synthesis method. The mechanisms for the nucleation, anisotropic growth, and morphological development under ultrasonic oscillations were comprehensively analyzed. The experimental outcomes revealed that the development of 1D Ag-Ga nanoalloys was in correlation with the ultrasonic exposure time, influencing the inter-/intraparticle interactions, modulating the Ga-(L) nano-/microsphere dimensional and structural properties, and establishing Ag-Ga bimetallic core-shell microsystems accordingly. The subsequent self-assembly mechanisms were observed to have been primarily driven by Ga-(L) surface tension and intermolecular forces promoting spontaneous Ag-Ga liquid-solid interfacial wetting and intermetallic diffusion. The nucleation and crystallization of the 1D nanoalloys developed following two possible pathways for the differentiation of morphologies in the form of either nanoneedles or nanorods identified as the Ag2Ga crystal phase. We observed that the key advantage of Ga-(L) nano-/microspheres as the reaction media is the direct control of the phase and morphological development of the 1D Ag-Ga batch structures, demonstrating a straightforward route for the green synthesis of engineered nanoalloys for catalytic applications.

Automated summary

In this study, one-dimensional silver-gallium (Ag-Ga) nanoalloys were successfully synthesized using liquid-phase gallium nano-/microspheres as reaction media. The green synthesis method involved ultrasonic input at near room temperature. The experimental outcomes revealed that the development of 1D Ag-Ga nanoalloys was influenced by the ultrasonic exposure time, leading to the formation of Ag-Ga bimetallic core-shell microsystems. The self-assembly mechanisms were primarily driven by Ga-(L) surface tension and intermolecular forces promoting intermetallic diffusion.