Sonochemical cavitation–driven interfacial-selective nucleation of silver nanoparticles via silver carboxylate precursors for Ag/Si nanocomposites

O, mixed carboxylic acids, and Si powder. Ultrasonic irradiation promoted the in situ formation and subsequent transformation of silver carboxylate intermediates, resulting in the formation of Ag nanoparticles on Si-particle surfaces. The formation and transformation behavior of these intermediates were influenced by the carboxylic acid composition and solvent type. Under formic acid-rich conditions, metallic Ag formation was promoted, whereas acetate-rich conditions resulted in the persistence of silver carboxylate phases. When 2-propanol was used as the solvent at an HCOOH ratio of 9:1, fine Ag nanoparticles were formed on the Si-particle surfaces. Particle-size analysis showed that the mean Ag nanoparticle diameter increased from 18.0 ± 6.0 nm after 2 h to 34.9 ± 16.4 nm after 3 h at 50 °C, indicating particle growth and/or coalescence during prolonged ultrasonic irradiation. A Si-free control experiment showed slower phase conversion and the formation of aggregated Ag-containing products, supporting the role of Si particles in influencing precursor transformation and Ag nanoparticle formation. These results are consistent with a cavitation-assisted interfacial process in which ultrasonic irradiation promotes silver carboxylate-mediated Ag formation and favors the formation of Ag nanoparticles at Si-particle interfaces. This process provides a potential route for preparing Ag/Si composite particles for Ag-based sintered materials, in which localized Ag loading may contribute to the efficient use of Ag.