▎ 摘　　要

Owing to the peculiar properties of graphene such as ultrahigh surface area and high strength, this fortified structure has been found to be efficient for swage and wastewater remediation, particularly for organic pollutant removal. Phenol and its derivatives are known as the priority of pollutants discharge from household and industrial processes and cause massive deleterious disturbance for human health and eco-environment. Numerous investigations have been earmarked to study the ability of graphene and graphene-based structures in wastewater remediation using various techniques. In this investigation, phenol removal ability of graphene and five distinct functionalized graphene structures, namely, phenyl-graphene, hydroxyl-graphene, graphene-oxide, carboxylgraphene and hydroxyphenyl-graphene arc studied using DFT-D3 calculations with revPBE/cle2-TZVP model of theory. Various configurations and binding sites were selected and appraised for phenol/water molecule approaching the graphene-based adsorbents. Our initial results showed that functionalized-graphene structures have more stability and are more efficient for phenol removal in comparison with pristine graphene. Hydroxyl-graphene can adsorb and remove phenol from wastewater compared to pristine graphene and other counterparts. The deprotanation of functional groups (hydroxyl- and carboxyl-graphene) due to the various pH values in the phenol adsorption was also investigated. The effect of van der Waals (vdW) forces, solvent and different molecular properties such as energy gap, hardness (q), softness (s), chemical potential (ii), and electron affinity (o)) were comprehensively discussed. (C) 2020 Elsevier B.V. All rights reserved.