Silver-Mediated Squaric Acid Reduction as a Facile, Ambient-temperature and Seedless Route to Tunable Bimetallic Au/Ag Nanostars and Nanosnowflakes

Bimetallic Au/Ag nanoparticles were successfully synthesized using a facile and reproducible method involving rapid, room-temperature mixing of aqueous solutions of HAuCl4 and AgNO3 in the presence of squaric acid as both the reducing agent and surface capping ligand. Variation in the initial Au : Ag molar ratio yielded a tunable anisotropic shape and affiliated surface plasmon resonance. The nanoparticles displayed excellent stability in water for at least 10 weeks and showed robust catalytic activity in the borohydride-assisted reduction of the model substrate 4-nitrophenol.

Automated summary

Bimetallic Au/Ag nanoparticles with tunable shape and excellent stability were successfully synthesized using a simple method. These nanoparticles showed robust catalytic activity in the reduction reaction.