Semmeq Abderrahmane, Anand Kanika, Carof Antoine, Bastida Adolfo, Ingrosso Francesca
Laboratoire de Physique et Chimie Théoriques UMR 7019, Université de Lorraine and CNRS, F-54000 Nancy, France.
Departamento de Química Física, Universidad de Murcia, 30100 Murcia, Spain.
Molecules. 2025 Apr 9;30(8):1678. doi: 10.3390/molecules30081678.
Understanding the microscopic structure and physical-chemical properties of materials with nanoconfined domains is essential for advancing technologies in catalysis, nanomaterial design, and pharmaceutical applications. Layered double hydroxides (LDHs) are promising candidates for such innovations due to their tunable interlayer environment, which can be precisely controlled by varying the type of intercalated anion and the amount of water present. However, optimizing LDH-based technologies requires detailed insights into the local structure within the interlayer region, where complex interactions occur among anions, water molecules, and the inorganic surfaces. In this work, we present a comprehensive computational study of LDHs intercalating small inorganic anions at varying hydration levels, using atomistic molecular dynamics simulations. Our findings show good agreement with existing experimental and simulation data. We observe that monoatomic ions form either a monolayered or double-layered structures, with water molecules lying flat at low hydration and adopting more disordered configurations near the surfaces at higher hydration. In contrast, polyatomic anions exhibit distinct structural behaviors: nitrates adopt tilted orientations and form double layers at high hydration, similar to perchlorates, while carbonates consistently remain flat. Additionally, water molecules strongly interact with both anions and the surface, whereas anion-surface interactions weaken slightly as hydration increases. These results offer valuable insights into the local structural dynamics of LDHs, paving the way for more efficient design and application of these versatile materials.
了解具有纳米受限域的材料的微观结构和物理化学性质对于推进催化、纳米材料设计和药物应用等技术至关重要。层状双氢氧化物（LDHs）因其可调节的层间环境而成为此类创新的有前途的候选材料，这种环境可以通过改变插层阴离子的类型和存在的水量来精确控制。然而，优化基于LDH的技术需要深入了解层间区域内的局部结构，在该区域阴离子、水分子和无机表面之间会发生复杂的相互作用。在这项工作中，我们使用原子分子动力学模拟对不同水合水平下插层小无机阴离子的LDHs进行了全面的计算研究。我们的研究结果与现有的实验和模拟数据显示出良好的一致性。我们观察到单原子离子形成单层或双层结构，水分子在低水合时平躺，在高水合时在表面附近采用更无序的构型。相比之下，多原子阴离子表现出不同的结构行为：硝酸盐在高水合时采用倾斜取向并形成双层，类似于高氯酸盐，而碳酸盐始终保持平躺。此外，水分子与阴离子和表面都有强烈的相互作用，而阴离子与表面的相互作用随着水合作用的增加而略有减弱。这些结果为LDHs的局部结构动力学提供了有价值的见解，为这些多功能材料的更高效设计和应用铺平了道路。
