Nanostructure characterization of polymer-stabilized gold nanoparticles and nanofilms derived from green synthesis

The fabrication and characterization of gold (Au) nanostructured materials draws significant attention because of their distinctive properties and their technological applications. The first objective of this study is to fabricate polymer-stabilized Au nanoparticles and nanofilms (PAN) through a cost effective and green synthetic methodology. In this study, the gold trication (Au³⁺) can be spontaneously converted into metallic gold atom using a non-toxic reductant (ascorbic acid). The ultrafine Au clusters were formed and stabilized through metallic bonds in the colloidal suspension, which was then deposited on a micro-glass or polymer-bead substrate to prepare thin films. It was found that ascorbic acid was the best reducing agent due to its rapid rate, spontaneity of reaction, and its non-toxic nature. In order to prevent aggregation of the nanoparticles, a dispersing agent (gum Arabic) was used. The second objective of this study was to analyze the PAN using a number of state-of-the-art instrumentation techniques and analytical approaches, such as X-ray powder diffraction (XRD), atomic force microscopy (AFM), scanning and transmission electron microscopy (SEM and TEM), ultraviolet–visible (UV–Vis) spectroscopy, and ZetaPALS. These techniques were applied to evaluate specific properties of the PAN, such as characterization of its crystalline phase, surface topology, characteristic plasmon, particle size distribution, and stability. From this study, it can be concluded that the ultrafine Au nanoparticles and uniform films were obtained using the green chemistry method. The ultrafine Au particles are highly stabilized and monodispersed as demonstrated by their high absolute value of zeta potential.