Synthesis and Applications of Graphene Oxide Based Nanocomposites in Wastewater Treatment and Antimicrobial Activity

Abstract

Globally, in the present scenario, the availability of clean water is a major challenge. Nanotechnology play a promising role in the decomposition of pollutants in water and air as well as removal of microbes. Among all, Graphene oxide (GO) based nanocomposites are the most promising nanomaterials used as a photocatalyst to remove contaminants from water and air. It is also used to kill or inhibit the growth of microbes. A photocatalyst generates reactive oxygen species (ROS) on solar light illumination which degraded the pollutants into less harmful products like CO2 and H2O etc. As the photocatalyst possesses some drawbacks like fast recombination of charge particles, limited absorption of visible light, and widened band gap which lessen their photocatalytic activity. To improve their photocatalytic efficiency there is some methods are used such as doping of metal or non-metal, by inserting carbon-based material like graphene, functionalized graphene (GO, rGO), fullerene, carbon nanotube (CNT) or forming composite form, etc. newline In the present work, GO-based binary nanocomposites TiO2/GO (T/G), and ZnO/GO (Z/G) are prepared with TiO2, ZnO nanoparticle (NPs), and ternary TiO2/ZnO/GO (TZG) with TiO2/ZnO (TZ) nanocomposites (NCs), respectively. GO is prepared by modified Hummer s Method. T/G and TZG are prepared by sol-gel, whereas ZnO/GO NCs is formed hydrothermally. The prepared all nanomaterials are characterized by various techniques to observe structural, morphological, and optical properties like Powder X-Ray diffraction (P-XRD), Field emission scanning electron microscopy (FE-SEM), Energy dispersive X-ray (EDX), High-resolution transmission electron microscopy (HR-TEM) and UV-Vis spectroscopy, Raman spectroscopy, etc. The P-XRD patterns revealed that all the prepared nanomaterials are in highly crystalline form. FE-SEM and HR-TEM explained that TiO2, ZnO NPs, and TZ NCs are well dispersed on the GO nanosheet making a compact-like structure that is favorable for photocatalysis. The stability of