Functionalized Graphene Oxide-MOF Modified Pencil Electrode for Heavy Metal Ions Detection

Abstract

viii Abstract Functionalized Graphene Oxide-MOF Modified Pencil Electrode for Heavy Metal Ions Detection By Sania Sakhawat In aqueous system, environmental pollution due to heavy metal ions is harmful for aquatic life as well as for human beings. Heavy metal ions cannot be degraded easily. Instead, they enter directly in human bodies or via food chain. Metal ions have the potential to change into more dangerous forms inside the body or have an immediate impact on metabolic processes. Heavy metal ions toxicity results in a number of various disorders. Therefore, there is a necessity for an effective strategy to detect HMIs. Numerous electrodes have been developed in this field for the purpose of detecting and removing toxic contaminants from aqueous systems. However, there is still a need to enhance the performance of sensors. In this particular investigation, a composite material comprising of graphene oxide (GO) and Metal-Organic Framework (MOF) ZIF-67 was synthesized. To detect Harmful Metallic Ions (HMIs), the modified composite material was applied to a pencil graphite electrode. The synthesis of graphene oxide involved a modified version of Hummer's method, while the MOF ZIF-67 was synthesized using a hydrothermal approach. Various characterization techniques such as FTIR, Raman, XRD, and SEM characterizations were performed to check synthesis. Electrochemical characterization was conducted using Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) techniques. A potential range of -0.6 to 0.6 mV, with a scan rate of 100 mV/s, was applied in the presence of a 5 mM [Fe (CN) 6]-3/-4 solution. DPV technique was performed to check electrochemical performance of modified electrode material to detect HMIs Calculated LOD for Pb+2 and Hg+2 was 0.01 μM and 0.04 μM respectively.