Biosynthesis of silver nanoparticles using Allium sativum extract assisted by solar irradiation in a composite with graphene oxide as potent adsorbents

Abstract

The present works describe a stable and facile biosynthesis of silver nanoparticles (AgNPs) from Allium sativum (A. sativum) cloves extract deposited on graphene oxide (GO). The AgNPs with different concentrations of [Ag(NH3)2]+ solution were synthesized under solar irradiation to catalyze the growth of AgNPs prior to the deposition on GO. Their adsorptivity was tested against methylene blue (MB) dye in aqueous media. Characterization analyses revealed that the silver nanoparticle-graphene oxide, Ag:GO-100 (S) nanocomposites were crystalline with asymmetrical spherical-shaped and well-dispersed on GO surfaces. The anchoring of AgNPs on GO sheets acts as spacers for the enhanced nanocomposites’ surface area and synergistically achieved almost a complete removal of MB dye in 5 min. The best rate constant of 4.97816 g mg−1 min−1 was obtained from the pseudo second-order kinetic model. The spontaneous adsorption mechanism was affirmed, and the nanocomposite potential could be exploited as an efficient, cost-effective, and feasible approach in the remediation of contaminated water, as a result of their outstanding performances.

Keywords

• Adsorbent
• Allium sativum
• Graphene oxide
• Methylene blue
• Silver nanoparticles