Acoustic levitation synthesis and subsequent physicochemical properties of bimetallic composite nanoparticles

Bimetallic noble-metal nanoparticles were synthesized in a containerless state via acoustic levitation. We chose oleylamine as stabilizer and borane-t-butylamine complex as reducing agent to prepare the Au-Ag nanoparticles in organic phase. The synthesis process, particle size distribution, morphology, optical property, chemical composition, and catalytic performance of prepared bimetallic nanoparticles were characterized and analyzed. The Au-Ag nanoparticles synthesized in acoustic levitation exhibited a smaller size, narrower distribution range, and improved catalytic performance in 4-nitrophenol reduction compared with the normal container condition. In acoustic levitation, the catalytic activity of equiatomic Au-Ag nanoparticles was significantly enhanced due to synergistic effects.