Removal of heavy metals from water through armchair carbon and boron nitride nanotubes: a computer simulation study

Abstract

Molecular dynamics simulations are used to study the removal of heavy metals from water using armchair carbon and boron nitride nanotubes and to analyse the transport of water molecules through the nanotubes under an applied electric field. The system includes a mixture of three heavy metals (Cu²⁺, Hg²⁺ and Pb²⁺) and a (7,7) carbon nanotube or a (7,7) boron nitride nanotube embedded in a silicon nitride membrane. An external electric field is applied to the simulated system for transporting ions. The results of the study indicate that the (7,7) nanotubes are capable of removing heavy metals with different ratios. The simulation results reveal that the removal of cations through armchair carbon and boron nitride nanotubes is attributed to the applied electric field. The phenomenon is explained with the potential of mean force. Moreover, the ionic current, water flow, normalized transport rate of water, and ion retention time are measured.