Dual-Functional Graphene-Based Flexible Material for Membrane Filtration and Electrochemical Sensing of Heavy Metal Ions

© 2001-2012 IEEE.Simultaneous removal and quantification of heavy metal ions are very important since they threaten human health. In this work, a dual-functional, free-standing and flexible reduced graphene oxide (rGO) based paper-like material including zinc oxide nanoparticles (ZnO-NPs) and ethylenediaminetetraaceticacid (EDTA) was produced using successive vacuum-filtration and hydrothermal reduction processes. First, graphene oxide (GO) layers were coated with ZnO-NPs and then EDTA was immobilized by ultrasonic treatment. Prepared GO/ZnO-NPs-EDTA suspension was vacuum-filtrated on a membrane and peeled to obtain GO/ZnO-NPs-EDTA paper. Hydrothermal reduction resulted in rGO/ZnO-NPs-EDTA paper and this material is first-time performed for two applications: Simultaneous removal of heavy metal ions of Cd2+, Pb2+, Cu2+, and Hg2+ and their further simultaneous electrochemical detection. Structural, chemical, crystallographic, optical, morphological, and electrochemical characterization of this paper-like material was executed using numerous techniques. Maximum adsorption performance of the rGO/ZnO-NPs-EDTA paper was determined as 2963, 8056, 600, and 1753 mg/g, while electrochemical simultaneous determination revealed linear ranges of 18.5-500, 22.4-700, 8.3-200, 3.3-300μ M and detection limit values of 5.6, 6.8, 2.5, 1.0μ M for Cd2+, Pb2+, Cu2+, and Hg2+, respectively.