Computational insights into the sorption mechanism of environmental contaminants by carbon nanoparticles through molecular dynamics simulation and density functional theory

Abstract

Carbon nanomaterials like carbon nanotube (CNT), graphene or graphene oxide (GO) could significantly enhance contaminant sorption in aqueous solutions, which offer a promising opportunity in water and air purification for...

Elucidating the Sorption Mechanisms of Environmental Pollutants Using Molecular Simulation

“…The most detailed MD technique to solve the quantum Schrodinger equation The effect of electrons is considered implicitly 46 Very accurate but computationally intensive Appropriate for systems containing 100−1000 atoms within a time duration of 1−100 ps Capable of investigating the phenomena containing chemical reaction, charge transfer, and electron excitation 46 DFT is the most extensively used form of AIMD, which relies on the electron density distribution 47 The system's configuration should be thoroughly known before starting DFT calculations 48,49 As shown in Table 3, the adsorbent's initial configuration considerably affects the adsorption type. It might change the adsorption process from physical to chemical, such as phenol adsorption using ZnO (the adsorption energy changed from −0.21 eV to −1.85 eV depending on the initial configuration).…”

“…When the adsorbent has a rotatable bond, the evolution of the torsional conformation can also be examined during the simulation. For example, Gao et al 48 examined the torsional conformation of 2,4,4′-trichlorobiphenyl (TCB) during adsorption on CNT and graphene. The results of dihedral distribution showed that there are two probable conformations; one is related to the TCB inner rotatable bond (about 0 degrees with the volatility of 40 degrees), and the other one is related to its relative position concerning CNT (about 120 degrees with the volatility of 15 degrees), and these are the most stable configurations, as it is shown in Figure 7b.…”

“…Furthermore, the functional groups and this ring intensify their interaction and make the adsorbent suitable for polar and ionic contaminants. 48 The adsorption energy and stability of pollutants with aromatic rings improve as the amount of aromatic rings increases in the adsorption process. This conclusion was also reported when adsorbing linear organic pollutants such as perfluorinated sulfonic acids and chlorinated paraffin, with the adsorption becoming more stable as the chain length of the pollutant increased.…”

“…As mentioned in the table, different reasons for starting configuration selection are stated. The best technique to study the possible binding modes is molecular docking. , However, when molecular docking is not applied, we cannot study all the various choices. In such situations, calculating the adsorbent’s electrostatic potential (ESP) and adsorbate is also a good suggestion.…”

Combining Experimental Isotherms, Minimalistic Simulations, and a Model to Understand and Predict Chemical Adsorption onto Montmorillonite Clays

“…This simpler approach dramatically increases both the length scale and time scale that can be simulated. Because of this, classical MD is an attractive approach to model clay systems and has been extensively used in the literature. ,− Structures of the chemical compounds adsorbed to the clay derived from MD simulations can provide insights into the interactions and orientation of the chemical compounds with inorganic surfaces. ,− ,− Studies that utilized these MD simulation methods have successfully characterized stable configurations and associated potential energies of various chemical compounds on clay surfaces. ,− …”