Synthesis, Characterization, and Antibacterial Activity of Graphene Oxide/Zinc Hydroxide Nanocomposites

Graphene and graphene oxide have shown good antibacterial activity against different bacterial species due to their unique physicochemical properties. Graphene oxide (GO) has been widely used to load metallic and metal oxide nanoparticles (NPs) to minimize their surface energy during processing and preparation, hence reducing their aggregation. In this work, GO was effectively synthesized and coated with different concentrations of zinc hydroxide Zn (OH)x using the precipitation method to prepare a GO/Zn (OH)x hybrid composite. The Zn (OH)x NPs and GO/Zn (OH)x nanocomposites were synthesized and characterized using various methods such as scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Coating GO with Zn (OH)x NPs resulted in improved aggregation of Zn (OH)x NPs as well as enhanced antibacterial activity of GO against Gram-positive and Gram-negative bacteria. Additionally, the effect of Zn (OH)x coating on the antibacterial properties of the GO/Zn (OH)x composite was systematically investigated. The synergistic effects of GO and Zn (OH)x NPs resulted in enhanced antibacterial properties of the composites compared to the pristine GO material. In addition, increasing the Zn (OH)x wt. % concentration led to an increased inhibition zone of the GO/Zn (H)x composite against Bacillus megaterium and E. coli bacteria.