School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng, 224051, China.
School of Chemistry and Chemical Engineering, Yancheng Institute of Technology, Yancheng, 224051, China; Department of Chemistry, Nanjing University of Science and Technology, Nanjing, 210094, China.
J Mol Graph Model. 2024 Jan;126:108644. doi: 10.1016/j.jmgm.2023.108644. Epub 2023 Oct 3.
In the process of degradation of aqueous fluoro-nitrobenzene (FNB) solution by titanium (Ti) electrode, the interaction between aqueous FNB solution and Ti electrode has an important impact on the performance and catalytic performance of electrode materials. The interaction involves complex physical, chemical and physical chemical processes, however, the mechanism of action is still unclear. In this study, Materials Studio software was used to design and construct molecular models of the interactions between aqueous FNB (p-, m-, o-FNB) solutions and Ti electrode, and molecular dynamics (MD) simulation was carried out in the absence of applied electric field and external electric field of 0.02 V/Å, respectively. Density functional theory (DFT) method was used to calculate the frontier molecular orbitals of three FNB molecules. Based on the calculation and analysis of the interaction energy (ΔE), diffusion coefficient (D) and radial distribution function (RDF), the interaction mechanism was discussed. It provides a theoretical basis for further research and development of Ti electrode degradation of fluorine compounds. The results showed that the order of ΔE between the three different aqueous FNB solutions and Ti surface is m-FNB > p-FNB > o-FNB when there is no external electric field. Under electric field of 0.02 V/Å, the order is p-FNB > m-FNB > o-FNB. The substitution position of F has an important effect on the HOMO of the nitro group and the LUMO of C-H in the three FNB molecules, and also affects the chemical reaction activity. In the model system, the diffusivity of different FNB solutions with electric field is less than that without electric field. The presence of an external electric field makes the diffusion of water and FNB molecules more orderly. The analysis results of RDF show that the bonding interactions between different FNB molecules and Ti surface is not much different before 3.5 Å, and all of them are weak. At about 8 Å, FNB molecule forms a non-bond with Ti electrode. ΔE, D and RDF of the model system can be changed by applying a certain external electric field, and the results are in better agreement with the experimental results.
在钛（Ti）电极降解水相氟硝基苯（FNB）溶液的过程中，水相 FNB 溶液与 Ti 电极之间的相互作用对电极材料的性能和催化性能有重要影响。这种相互作用涉及复杂的物理、化学和物理化学过程，但作用机制尚不清楚。在本研究中，使用 Materials Studio 软件设计并构建了水相 FNB（对、间、邻-FNB）溶液与 Ti 电极相互作用的分子模型，并分别在无外加电场和外加电场 0.02V/Å 的条件下进行了分子动力学（MD）模拟。使用密度泛函理论（DFT）方法计算了三种 FNB 分子的前线分子轨道。基于相互作用能（ΔE）、扩散系数（D）和径向分布函数（RDF）的计算和分析，探讨了相互作用机制。为进一步研究和开发 Ti 电极降解氟化合物提供了理论依据。结果表明，在外加电场为 0.02V/Å 时，三种不同水相 FNB 溶液与 Ti 表面的相互作用能顺序为 m-FNB＞p-FNB＞o-FNB；无外加电场时，相互作用能顺序为 m-FNB＞p-FNB＞o-FNB。F 取代位置对三种 FNB 分子中硝基的 HOMO 和 C-H 的 LUMO 有重要影响，也影响化学反应活性。在模型体系中，外加电场下水相 FNB 溶液的扩散系数均小于无电场时的扩散系数。外加电场的存在使水和 FNB 分子的扩散更加有序。RDF 分析结果表明，不同 FNB 分子与 Ti 表面的键合相互作用在 3.5Å 之前差异不大，均为弱相互作用。在约 8Å 处，FNB 分子与 Ti 电极形成非键合。施加一定的外加电场可以改变模型体系的ΔE、D 和 RDF，结果与实验结果更为吻合。
