(515g) Computational Screening of Synergistic 2D Materials Impregnated with Deep Eutectic Solvents for Removal of Pharmaceuticals

This study introduces a groundbreaking approach in the domain of water treatment technology, emphasizing the integration of a molecular modeling framework to pinpoint the most effective two-dimensional (2D) materials for the removal of pharmaceuticals from aqueous solutions. The research specifically focuses on graphene (Gr), graphene oxide (GO) and reduced graphene oxide (rGO), used with natural deep eutectic solvents (NADESs), a relatively underexplored class of eco-friendly solvents that offer potential for environmental remediation applications.

The initial phase of the research involved an extensive list of over 100 potential that can make NADESs. This foundational work set the stage for further experimental investigations. The next step involved employing Density Functional Theory (DFT) using the Materials Studio software with the General Gradient Approximation (GGA) and Dmol3 PBE functional. The results from these DFT calculations were used to generate COSMO files, which then served as inputs for the Conductor-like Screening Model for Real Solvents (COSMO-RS) analysis. The results of the DFT calculations were used to create COSMO files. These files then provided the basis for COSMO-RS analysis. Using COSMOthermX software, we calculated the activity coefficients at infinite dilution for the 2D materials including Gr, GO, and rGO, alongside water molecule, natural compounds and pharmaceutical pollutants, including antibiotics like Meropenem, Tetracycline, and Ciprofloxacin. The screening process concentrated on two pivotal performance metrics: affinity and selectivity at infinite dilution. These metrics are critical for determining the practical applicability of the materials in water treatment processes, where efficient and selective adsorption of contaminants is required.

Our findings demonstrate that GO has a significantly high affinity for a wide range of pharmaceutical substances, as evidenced by its activity coefficient at infinite dilution of -4,968. This performance markedly surpasses that of rGO and Gr, which recorded coefficients of 3,454 and 10,124, respectively, highlighting GO's enhanced capability in trapping these pollutants. Further investigation into NADESs revealed that among the terpene and terpenoid family compounds, thymol exhibited the highest affinity towards antibiotics with an activity coefficient of -6.487. This was significantly better compared to other tested natural compounds like menthol at 3.399, camphor at 3.035, and coumarin at 1.867. These findings underscore the potential of environmentally friendly compounds in the development of sustainable water treatment technologies.

In summary, this research provides profound molecular-level insights into removing pharmaceuticals from water using GO and NADESs. The outcomes not only contribute significantly to the understanding of 2D material-NADES interactions but also lay a robust foundation for future explorations. These future efforts will likely include the synthesis and characterization of synergistic 2D-NADES-based adsorbents tailored explicitly for the enhanced removal of pharmaceutical contaminants from aqueous media. The implications of such developments could be transformative for environmental protection strategies, offering scalable, practical solutions to one of the most pressing issues in water treatment.