A combined DFT, Monte Carlo, and MD simulations of adsorption study of heavy metals on the carbon graphite (111) surface

This work investigated the adsorption mechanism of heavy metals: silver (Ag), mercury (Hg), cadmium (Cd), palladium (Pd), and zinc (Zn) on the carbon graphite (111) surface based on density functional theory (DFT), Metropolis Monte Carlo (MMC), and the molecular dynamics (MD) simulation methods. The obtained results from the adsorption of these species showed that the process is spontaneous and exothermic in nature. The maximum adsorption capacities were obtained in neutral to low acid medium, and the interaction between Hgcarbon graphite was more favored than other systems. These findings showed that carbon graphite was more efficient in the removal of the studied metals. Moreover, this study better explains the adsorption mechanism of heavy metals onto carbon graphite and gives a theoretical basis for the wider application of graphite adsorbent in the removal of heavy metals. This paper provides theoretical support for heavy metals removal in various mediums and also provides some new ideas for the secondary utilization of quantum chemical descriptors and molecular dynamics simulation methods.