WITHDRAWN: Utility of Warped C80H30 nanographene for removal of toxic heavy metal ions from wastewater

Abstract

The removal of heavy metal ions from wastewater has been a global issue as such ions pose significant health and environmental impacts. Drawing on a nanographene (NG), the present study employs density functional theory (DFT) to evaluate an effective heavy metal removal method for the purpose of removing Pb 2+ , Hg 2+ , and Cd 2+ ions from wastewater. NG was found to have high effectiveness and efficiency in capturing the heavy metals of aqueous media. Furthermore, the adsorption of Pb 2+ , Hg 2+ , and Cd 2+ ions was found to have the capability of diminishing the significant pristine NG (HOMO-LUMO) gap. The findings showed larger cation-NG charge transfers and greater binding energy in cation-NG systems that have larger transport rates of electrons. According to the time-dependent DFT results, the complexes under study were found to have “ligand-to-metal charge transfer” excitations. As a result, the theoretical findings of the present work could contribute to experimental works on identifying NG-based efficient and effective substances for the removal of contaminants from wastewater. • The first DFT study on the adsorption of pollutant Cd 2+ , Hg 2+ , and Pb 2+ ions on NG layer. • Detailed analysis of possible charge transfers between the cations and the NG. • TD-DFT analysis showed “ligand to metal charge transfer” excitations for the complexes.