Atrazine (A) is one of the most applied herbicides and has a negative impact on the environment and health. Density functional theory (DFT) and experimental methods were used in the study of the immobilization of atrazine in two smectites, montmorillonite (Mt) and beidellite (Bd), as well as in their organically modified structures. Four systems were examined: A-Mt and A-Bd, as well as the structures modified by tetramethylphosphonium cation (TMP), A-TMP-Mt and A-TMP-Bd. The calculations revealed a flat arrangement of the atrazine in the interlayer space of both smectites with higher stability of beidellite structures. The presence of the TMP cation increased the fixation of atrazine in both organically modified smectites. The calculated vibrational spectra allowed a detailed analysis of the overlapping bands observed in the experimental FTIR spectra and their correct assignment. Further, selected FTIR bands unambiguously assigned to atrazine and both smectites served for the estimation of the adsorbed amount of atrazine. It was shown that the adsorption capacity of both TMP-modified smectites did not increase in comparison to the adsorption capacity of unmodified smectite samples.

Topological defects in graphene, such as Stone–Wales rearrangements and non-hexagonal ring formations, significantly reshaped its electronic landscape and unlocked new adsorption pathways. Using density functional theory (DFT), this study revealed how these defects influenced the interaction with CO₂ and NH₃ molecules. The findings demonstrated that defect-induced distortions and localized electron density variations created active sites that enhanced molecular interactions. The interplay between defect geometry and molecular orientation governed adsorption strength, with defective graphene models containing 5-, 7- and 8-membered rings, showing enhanced adsorption energies compared to pristine graphene, particularly for NH₃ molecules. Particularly, the model with 5- and 8-membered ring defects (MG8) exhibited the strongest interactions for both CO₂ and NH₃. These results underscore the potential of tailoring graphene's defects for advanced gas storage, sensing, and catalysis applications, opening new avenues for designing more efficient graphene-based materials with tunable adsorption properties.