Mortiño (Vaccinium floribundum Kunth) berry assisted green synthesis and photocatalytic performance of Silver–Graphene nanocomposite

Abstract

Mortiño (Vaccinium floribundum Kunth) is a wild shrub native to South America, whose berries are widely consumed in Ecuador as fresh fruit, juice and jam. We reported a green synthesis of Silver–Graphene (Ag-G) nanocomposite through the reduction of Ag+ and graphene oxide using berry extract of Mortiño. Silver nanoparticles were anchored onto the graphene sheets by ultrasonication and solar light irradiation. The as-prepared Ag-G nanocomposite was characterized by Fourier transform infrared spectroscopy, UV–vis spectroscopy, Scanning transmission electron microscopy, Scanning electron microscopy with energy dispersive X-ray spectrometry, and X-ray diffraction techniques. The photocatalytic activities of the Ag-G nanocomposite were evaluated by the degradation of methylene blue (MB) and methylene orange (MO) in an aqueous medium under sunlight irradiation. The photocatalytic activity of Ag-G nanocomposite for the degradation of MB (k = 0.0163283 min−1) > MO (k = 0.0140985 min−1), due to the anchoring of Ag nanoparticles on the graphene sheets and thiazine ring of MB is more susceptible to photodegradation than the azo bond of MO. This ecofriendly and green reduction method avoids the use of toxic reagents, and it might be useful for biocompatible materials in the future engineering applications.