DFT insight into Cd2+, Hg2+, Pb2+, Sn2+, As3+, Sb3+, and Cr3+ heavy metal ions adsorption onto surface of bowl-like B30 nanosheet

Contamination of water resources by heavy metal ions, is a drastic environmental concern. In this study, the interaction of Cd2+, Hg2+, Pb2+, Sn2+, As3+, Sb3+, and Cr3+ metal ions onto surface of the bowl-like B-30 nanosheet was scrutinized based on density functional theory (DFT) calculations. Adsorption energy (E-ads) values revealed that the As(3+ )interacted better with bowl-like B-30 nanosheet in comparison to other metal ions, having adsorption energy values of-299.57 and -628.56 kcal mol(-1) in the gas phase and aqueous media, respectively. However, Hg2+, Pb2+, and Sn2+ metal ions physically adsorbed onto bowl-like B-30 nanosheet in the gas phase because of their much less value of adsorption energy. The sign of adsorption Gibbs free energy change (delta G(ads)) and adsorption enthalpy change (delta H-ads) values for all complexes was found to be negative in the gas phase and aqueous media, which indicated that the adsorption process is spontaneous and exothermic. Frontier molecular orbital (FMO) analysis exhibited a decrease in the HOMO-LUMO energy gap of studied complexes, boosting the electrical conductivity of these complexes. Natural bond orbital (NBO) analysis and charge decomposition analysis (CDA) revealed donor-acceptor charge transfer interactions in the complexes. The UV-vis results depicted that lambda(max) was red-shifted during interactions of meal ions with bowl-like B-30 nanosheet. Finally, quantum theory of atoms in molecules (QTAIM) exhibited that the interaction between As3+ metal ion and the nanosheet is covalent in nature, while the other metal ions have predominantly electrostatic with partially covalent and non-covalent characters. The theoretical results of the study represented the feasibility of applying bowl-like B-30 nanosheet to remove heavy metal ions, especially As3+ and providing information for experimental researchers to treat wastewaters.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, the interaction between different heavy metal ions and bowl-like B-30 nanosheet was analyzed using density functional theory calculations. The results showed that the bowl-like B-30 nanosheet exhibited better adsorption performance towards As3+ ion, indicating its potential application for heavy metal ion removal.