An Investigation of Silver Nanoparticles Formation under Presence of Graphene Quantum Dots as Reducing Reagent and Stabilizer

In this work, we have studied effect of various reaction conditions for silver nanoparticles (AgNPs) production by a green and simple method. In our proposed method, silver nanoparticles have been formed and growth under presence of graphene quantum dots (GQDs) as reducing reagent and stabilizer. First, the small sized graphene quantum dots (GQDs) (5 nm +/- 2 nm) with abundant oxygen containing functional groups have been synthesis by hydrothermal method, then GQDs have been used to adsorb Ag+ ions from solution onto GQDs's surface and after that, Ag+ ions have been reduced into silver nanoparticles (AgNPs) by GQDs without adding any reducing reagents. GQDs were coated on the surfaces of the resultant AgNPs, leading to the formation of AgNPs/GQDs nano-hybrids. The optimized reaction conditions (such as pH, reaction time, temperature(+)) for synthesis of AgNPs using GQDs as a reducing reagent and stabilizer have been investigated. The synthesized AgNPs/GQDs have been characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Ultraviolet-visible spectroscopy (UV-Vis), and Dynamic Light Scattering (DLS). Results indicated that mono-dispersed AgNPs were obtained with particles size around 20nm-40 nm.