TiO₂-modified activated carbon for pharmaceutical contaminant removal: experimental and in-silico insights using density functional theory.

Mitigating the pollution of water by emerging contaminants (ECs) presents a critical environmental challenge that demands innovative, effective, cost-efficient, and sustainable strategies. In this study, the potential of TiO₂-modified activated carbon (AC) for the sequestration of ECs from water was evaluated through a combined experimental and in silico approach, using molecular modeling based on density functional theory (DFT). Unmodified AC removed 67.76-82.09% of ECs such as carbamazepine, flumequine, clarithromycin, azithromycin, and roxithromycin, and 44.54-52.27% of sulfamerazine, sulfamethoxazole, sulfamonomethoxine, trimethoprim, and levofloxacin. Incorporating TiO₂ and utilizing sunlight improved removal efficiencies to 93.09-99.91%. The hydrophobicity of contaminants significantly influenced adsorption. Kinetic and isotherm analyses indicated chemical interaction-driven, monolayer adsorption, with the Langmuir model fitting best (R² = 0.9856-0.9975). Textural analysis of TiO₂-AC (10% TiO₂) revealed a surface area of 557.72 m²·g⁻¹ and a pore volume of 0.317 cm³·g⁻¹, supporting its high adsorption potential. Fourier transform infrared spectroscopy and molecular modeling identified functional groups facilitating adsorption, while DFT provided insights into energetic and non-covalent interactions (NC-interaction) including hydrogen bonding, van der Waals forces (VDW-forces), and charge transfer that occur during the process. TiO₂-modified AC demonstrates high efficiency for pharmaceutical removal from water, highlighting great promise as a sustainable and advanced adsorbent material, offering practical solutions for tackling diverse water pollution challenges. The online version contains supplementary material available at 10.1007/s40201-025-00966-w. © The Author(s), under exclusive licence to Tehran University of Medical Sciences 2025. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.