Combined Monte Carlo simulation and DFT calculations of Auramine O adsorption onto nickel ferrite in water

This research focused on investigating the adsorption behavior of Auramine O (AO) dye on the nickel ferrite (NiFe2O4) surface, aiming to enhance the understanding of the adsorption mechanism using advanced techniques such as Density Functional Theory (DFT) and Monte Carlo simulations (MCS). The results obtained from the adsorption study of AO demonstrate that the adsorption mechanism is thermodynamically favorable and exothermic in nature. The investigation revealed that the highest adsorption energy, reaching −1340.119 kcal/mol, was achieved in an acidic medium. This indicates a stronger and more favorable interaction between AO and the NiFe2O4 material in acidic conditions compared to neutral and basic mediums, which exhibited lower adsorption energies of −440.092 kcal/mol and −246.212 kcal/mol, respectively. This observation suggests that NiFe2O4 sorbent has significant potential as an effective and successful adsorbent for removing these species via an acidic phase. Furthermore, this study provides a deeper understanding of the dye adsorption mechanism on the NiFe2O4 surface, offering a theoretical foundation for the broader application of NiFe2O4 based adsorbents in dye removal processes. By elucidating the thermodynamic nature of the adsorption mechanism and identifying a powerful and significant interaction between two entities (AO dye and the NiFe2O4 adsorbent). These results are potentially useful in developing more effective and sustainable strategies for dye decontamination, which is a critical challenge for protecting human health and the environment.