Controlled synthesis and characterizations of reduced graphene oxide silver nanohybrids using monosaccharides

The present study aims to develop a simple, non-toxic, and environmentally friendly reduced graphene oxide-silver (rGO-Ag) nanohybrid synthesis method by employing three monosaccharides which are ribose, fructose, and galactose, as the reducing agents. This study also investigated the formation and crystalline structures of the rGO-Ag formed. The resultant nanohybrids were characterised via ultraviolet-visible absorption (UV-vis), X-ray diffraction (XRD), and field emission scanning electron microscope (FESEM). The UV-vis results indicated that galactose was the most efficient reducing agent. The broadest peak recorded by the rGO-Ag reduced with galactose [rGO-Ag (Gal)] at 271 nm, while the narrowest peak observed at 423 nm corresponded to the formation of silver nanoparticles (AgNPs) on the rGO. The nanohybrids procured with the other reducing agents were also evaluated with XRD. The oxygen and carbon compositions of the samples were also analysed via FESEM equipped with energy-dispersive X-ray (EDX). The average particle size calculated based on the rGO-Ag (Gal) XRD results was the smallest (6 nm) compared to the other two monosaccharides. Furthermore, the d-spacing of the rGO-Ag (Gal) was almost identical to the XRD data, confirming the high-resolution transmission electron microscopy (HRTEM) findings. Consequently, galactose was the ideal reducing agent to synthesise rGO-ag nanohybrids.