Characterization and Synthesis of Silica-Coated Silver Nanoparticles by Sol-Gel Method with Controlling of Adding Ammonical Silver Nitrate Amount

Abstract

In this study, silica-coated silver nanoparticles (SSNPs) with a core–shell structure are successfully fabricated using a simple sol-gel method without using primer, surfactant or surface modification of core. To investigate the influence of ammonical silver nitrate (AgNO3) on the synthesis of SSNPs, the amount of an aqueous solution of AgNO3 was varied in the range from 3 to 12 mL. It was found that the thickness of silver shell could be formed in the range of ∼20 to ∼60 nm, and the UV–vis optical absorption measurement revealed a pronounced red-shift of the surface plasmon resonance (SPR) band from 442 to 516 nm.