Pre-synthesis theoretical screening of pristine and B- and Si-doped C24 fullerene and coronene nanostructures for aqueous santenol adsorption in wastewater-remediation applications

Abstract In this work, density functional theory (DFT) and time-dependent DFT calculations were used to investigate Santenol (Pollutant present in wastewater) adsorption on two carbon frameworks containing the same number of carbon atoms but differing substantially in topology, hydrogen termination, strain, electronic structure, and overall composition: C24 fullerene and coronene (COR), as well as their B- and Si-doped derivatives. We used geometry optimization, adsorption energy, cohesive energy, recovery time, electronic descriptors, a gap-derived electronic-response index, UV–Vis response, NBO, MEP, DOS, HOMO-LUMO, ELF, LOL, and NCI/RDG analyses to evaluate adsorption behavior and potential sensing properties. Adsorption-energy calculations indicated that B-C23 and SiC23 exhibit the strongest STN adsorption, with Eads values of – 51.83/– 54.77 and − 42.80/– 46.82 kcal.mol⁻¹ at the B97D/ωB97X-D levels, respectively. Thermodynamic analyses, including ΔHads and ΔGads, confirmed the favorable adsorption conditions for these structures. This suggests their potential as strong molecular adsorption candidates for STN under continuum-aqueous conditions and supports their further evaluation in wastewater-remediation-oriented studies. Thermodynamic analysis further showed that B-C23@STN exhibits the most favorable adsorption, with ΔGads = – 39.28 kcal.mol⁻¹, whereas COR@STN shows a slightly positive ΔGads = + 0.76 kcal.mol⁻¹ under the adopted standard-state computational conditions. In contrast, COR and B-COR showed weaker adsorption and comparatively small nominal τ values within the simplified desorption model, consistent with more reversible adsorption behavior. Electronic and optical analyses revealed adsorption-induced changes in the HOMO-LUMO gap, gap-derived electronic-response index, and λmax, particularly for B-COR, Si-COR, and B-C23. The large red shifts observed for B-COR@STN and B-C23@STN suggest a possible optical response toward STN. The combined NBO, MEP, ELF/LOL, NCI/RDG, and QTAIM analyses indicate that the extended adsorption interfaces contain substantial π-related, dispersion, and electrostatic contributions, whereas selected dopant–nitrogen contacts, particularly in B-C23@STN and Si-C23@STN, exhibit stronger localized donor–acceptor interactions with appreciable partial-bonding character. Overall, these computational results suggest that C24- and COR-based systems may serve as theoretical candidate platforms for guiding future experimental STN (as a model drug-like contaminant) adsorption and response-screening studies.