Polydopamine functionalized graphene sheets decorated with magnetic metal oxide nanoparticles as efficient nanozyme for the detection and degradation of harmful triazine pesticides

摘要

A facile and an eco-friendly reduction and functionalization of reduced graphene oxide (rGO) sheets is carried out using dopamine and decorated with magnetic Fe3O4 nanoparticles with an average size of 12 nm by a simple co-precipitation method which is established as an artificial nanozyme. Here, functionalization of graphene using dopamine has introduced several advantages and insights into this study. The Fe(3)O(4 )nanoparticles decorated functionalized rGO sheets (FDGs) nanozymes are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, atomic force microscopy (AFM), thermogravimetric (TGA) and vibrating sample magnetometer (VSM) analysis. FDGs nanozymes exhibits dual characteristics towards detection and degradation of harmful simazine pesticide. The hydrogen bonding interactions between pesticide molecules and 3,3',5,5'-tetramethylbenzidine (TMB) causes inhibition of the catalytic activity of the FDGs towards oxidation of TMB molecule. Based on that, the presence of simazine pesticide in an aqueous medium can be easily determined and a certain value (2.24 mu M) of detection limit was achieved. The photocatalytic degradation of simazine is also executed and excellent photocatalytic activity was observed under irradiation of direct natural sunlight. The FDGs nanozyme is also reusable up to several times with insignificant loss in its catalytic activity towards simazine degradation. (C) 2020 Elsevier Ltd. All rights reserved.