Molecular dynamics simulation study of heavy metal ions accumulation between graphene nano-channel under external electric field

Heavy metal ion remediation from water system through accumulation using external electric field is proposed. Here, graphene nano-channel is utilized for heavy metal accumulation under different magnitude of electric fields (1.0 V/Å, 1.5 V/Å, and 2.0 V/Å). Molecular dynamics simulation was carried out in three phases i.e. initiation, accumulation, and cleaning phase. Cadmium, mercury, and lead heavy metal ions were selected and relative position, distance, energy, and radial distribution function were evaluated. The results show that the electrostatic attraction between the positively charged heavy metal ions and the negatively charged graphene nano-channel significantly increases with the increase in the magnitude of the external electric field, consequently enhancing ion accumulation. The interaction of the ions with the graphene nano-channel at the external electric field of 1.5 V/Å was found to be suitable.