Which is better for Lindane pesticide adsorption, graphene or graphene oxide? An experimental and DFT study

Abstract

Graphene and graphene oxide are fascinating materials with a wide range of uses ranging from adsorption to photovoltaics. Graphene oxide is synthesized in this work by reducing graphene oxide (with ascorbic acid) using a well-established Hummers process, which is summarized as controlled treatment of graphite flakes with potassium permanganate in concentrated sulphuric acid. FTIR and UV–VIS spectroscopy are used to characterize the synthesized materials. The adsorption of Lindane in hexane is carried out using a solution with a concentration range of 25 to 500 ppb and a constant mass of 15 mg graphene or graphene oxide. The GC-ECD was used to determine the Lindane adsorbed concentration. These materials have remarkable absorptive characteristics. Up to 92.5 percent of Lindane is removed from hexane solution using graphene and up to 56.1 by graphene oxide. Theoretical calculations based on quantum and molecular mechanics were performed to better understand the interaction nature and energetics of Lindane with the two adsorbents.