Ascorbic Acid-assisted Green Synthesis of Silver Nanoparticles: pH and Stability Study

Abstract

In this chapter, eco-friendly in situ synthesis of silver nanoparticles (AgNPs) using a mixture of ascorbic acid and citric acid is introduced. The synthesis conditions of the AgNPs were optimized by adjusting the pH of the reaction mixture. Different spectroscopic and microscopic techniques have been used to characterize the physico-chemical properties of AgNPs. The synthesis of AgNPs was primarily identified by the appearance of yellow colour and confirmed by showing λmax = 409 nm in UV-visible spectroscopy. All characterization techniques reveal that the generated AgNPs were non-aggregated, quasi-spherical shapes with an average size of 22.4 ± 13.2 nm, and face-centred cubic crystalline structures. Infrared spectroscopy confirms the surface of AgNPs covered with -COOH group and shows peaks at 1733, 1759, 3262 and 3633 cm−1. Moreover, synthesized AgNPs at pH 10 were stable for one month with a slight change in size. A straightforward, facile and environmentally-friendly synthesis of highly stable AgNPs may contribute to future engineering applications.