El-Sheikh Abdel Salam, Abdelaziz Nabil S, Amin Khaled S, Elhaes Hanan, Ibrahim Medhat A
Regional Center for Food and Feed RCFF, Giza, Egypt.
Physics Department, Faculty of Science, Mansoura University, Mansoura, 35516, Egypt.
Sci Rep. 2025 Aug 7;15(1):28905. doi: 10.1038/s41598-025-13307-6.
Water pollution caused by heavy metals such as lead (Pb) and copper (Cu) represent a critical global challenge due to their toxicity and adverse impacts on both human health and the environment. Among several remediation methods, adsorption using polymer-based sorbents like chitosan (Cs) has emerged as a promising approach. In this study, chitosan interacted with graphene (Gr) and graphene oxide (GrO) to enhance its possible interaction with di-hydrated Pb and Cu. The electronic properties of Cs/Gr and Cs/GrO composites were studied using density functional theory (DFT) at the B3LYP/LANL2DZ level of theory. Physical parameters, including total dipole moment (TDM), HOMO-LUMO energy gap (∆E), and global reactivity descriptors, were calculated. Additionally, molecular electrostatic potential (MESP), density of states (DOS), and frontier molecular orbitals (FMO) were analyzed. The results demonstrated significant improvements in electronic properties, with increased total dipole moment (TDM) values (7.300 Debye for Cs/Gr and 6.311 Debye for Cs/GrO) and reduced ∆E (3.671 eV for Cs/Gr and 2.701 eV for Cs/GrO), indicating enhanced reactivity. Adsorption energies (E) for interactions with di-hydrated Pb and Cu were also evaluated, showing proper binding where E values of – 13.869 eV for Cs/Gr/di-hydrated Pb, – 13.689 eV for Cs/Gr/di-hydrated Cu, – 12.975 eV for Cs/GrO/di-hydrated Pb, and − 14.211 eV for Cs/GrO/di-hydrated Cu. Quantum Theory of Atoms in Molecules (QTAIM) analysis confirmed E findings. Cs/GrO composites were synthesized and FTIR spectra were measured and compared to computed vibrational frequencies. This study combines DFT and QTAIM to provide a comprehensive understanding of the selective adsorption behavior of Cs/Gr and Cs/GrO composites for di-hydrated Pb and Cu, supported by FTIR validation of the computational models.
铅（Pb）和铜（Cu）等重金属造成的水污染因其毒性以及对人类健康和环境的不利影响，成为了一项严峻的全球性挑战。在多种修复方法中，使用壳聚糖（Cs）等基于聚合物的吸附剂进行吸附已成为一种很有前景的方法。在本研究中，壳聚糖与石墨烯（Gr）和氧化石墨烯（GrO）相互作用，以增强其与二水合铅和铜的可能相互作用。使用密度泛函理论（DFT）在B3LYP/LANL2DZ理论水平上研究了Cs/Gr和Cs/GrO复合材料的电子性质。计算了包括总偶极矩（TDM）、HOMO-LUMO能隙（∆E）和全局反应性描述符在内的物理参数。此外，还分析了分子静电势（MESP）、态密度（DOS）和前线分子轨道（FMO）。结果表明，电子性质有显著改善，总偶极矩（TDM）值增加（Cs/Gr为7.300德拜，Cs/GrO为6.311德拜），∆E减小（Cs/Gr为3.671电子伏特，Cs/GrO为2.701电子伏特），表明反应性增强。还评估了与二水合铅和铜相互作用的吸附能（E），显示出合适的结合，Cs/Gr/二水合铅的E值为–13.869电子伏特，Cs/Gr/二水合铜的E值为–13.689电子伏特，Cs/GrO/二水合铅的E值为–12.975电子伏特，Cs/GrO/二水合铜的E值为−14.211电子伏特。分子中的原子量子理论（QTAIM）分析证实了E的结果。合成了Cs/GrO复合材料，并测量了FTIR光谱，并与计算出的振动频率进行了比较。本研究结合DFT和QTAIM，在计算模型的FTIR验证支持下，全面了解Cs/Gr和Cs/GrO复合材料对二水合铅和铜的选择性吸附行为。
