Size-Controlled Synthesis and Self-Assembly of Silver Nanoparticles within a Minute Using Microwave Irradiation

Size-controlled silver (Ag) nanoparticles (NPs) and nanochains were synthesized for the first time in large quantities. This was done in the presence of alkaline 2,7-dihydroxy naphthalene (2,7-DHN) as a new reducing agent under microwave heating for just 60 s in a nonionic surfactant (TX-100) media. Results showed that the Ag NPs were small in size, which could be successfully controlled through varying the TX-100 to Ag(I) molar ratio. The formation of Ag nanochains was enhanced by low TX-100 concentrations and high pH. The synthesized particles are stable for more than 3 months in ambient conditions. The proposed method could be extended for the synthesis of other metal and semiconductor nanomaterials with defined sizes and shapes. These particles could find valuable applications in catalysis, nanoelectronics, and surface-enhanced Raman spectroscopic (SERS) studies.