DFT analysis of phosphorene and oxidized phosphorene as Cu2+ adsorbent materials from aqueous solution [Análisis DFT de fosforeno y fosforeno oxidado como materiales adsorbentes de Cu2+ a partir de una solución acuosa]

Abstract

We conducted a systematic study using the density functional theory (DFT) to provide a better understanding of the role of oxygen concentration in pristine phosphorene during Cu2+ adsorption in aqueous systems. The electronic characterization of phosphorene and oxidized phosphorene was done by calculating the gap and the chemical hardness. From the results, we concluded that the oxidized systems have a lower gap and hardness than the pristine system and that as the oxygen concentration increases, these values decrease compared to the other systems. The interaction of Cu2+ with the different surfaces was characterized using atomic charges, bond index, and X-Ray Photoelectron Spectroscopy (XPS). The adsorption energy values indicated that when phosphorene is oxidized, the interaction with Cu2+ is stronger compared to the pristine system and that the increase in the oxygen concentration also increases the adsorption capacity of phosphorene, which is related to the ease that this system has for the transfer to Cu2+ due to its small gap and chemical hardness values. Our results contribute to a better understanding of the effect of phosphorene surface oxygen concentration on Cu2+ adsorption reinforcing the idea that this type of 2D materials may potentially be used for heavy metal removal from wastewater. © 2023 Colombian Academy of Exact, Physical and Natural Sciences. All rights reserved.