Removal of heavy metal ions in wastewater by using aluminum carbide (AlC) monolayer

Abstract

First-principles calculations were undertaken for the sake of comparing the adhesion of a number of heavy metal ions (HMIs), like Hg²⁺, Cd²⁺, and Pb²⁺, in wastewaters onto aluminum carbide monolayer (hereafter AlCML) for maximizing the potential of this monolayer in disposing these HMIs in wastewaters. As the simulation results showed, because of the attractive interactions between HMIs and the AlCML, the AlCML can be considered a promising adhesion material for these HMIs. The Al site was the ideal site for the adhesion of these ions, based on the most negative adhesion energy. The value of adhesion energy for the metal’s Cd²⁺, Pb²⁺, and Hg²⁺at the most stable site on the nanosheet was found to be −3.34, −4.56, and −0.83 eV, respectively. The attractive interactions were regarded as chemisorption, having a close relationship with charge transport. The charge transfer values for Cd²⁺ and Pb²⁺ were found to be 0.421e and 0.396e, respectively. The adhesion was facilitated due to the orbital hybridization between the p and d states of the ions and the p state of the Al atoms. Ultimately, the findings demonstrated the possibility of using the AlCML in order remove Pb²⁺ and Cd²⁺ from wastewaters.