Lin Yuanchuang, Cheng Ruihuan, Liang Tiangui, Wu Weixiong, Li Song, Li Wei
Energy & Electricity Research Center, Jinan University, Zhuhai, 519070, China.
Department of Mechanical Engineering, The University of HongKong, Pokfulam Road, HongKong SAR 999077, China.
Phys Chem Chem Phys. 2023 Dec 6;25(47):32407-32415. doi: 10.1039/d3cp04640k.
The thermal conductivity of metal-organic frameworks (MOFs) has garnered increasing interest due to their potential applications in energy-related fields. However, due to the diversity of building units, understanding the relationship between MOF structures and their thermal conductivity remains an imperative challenge. In this study, we predicted the thermal conductivity () of MOFs using equilibrium molecular dynamics (EMD) simulations and investigated the contribution of structure properties to their thermal conductivity. It is revealed that the arrangement of secondary building units (SBUs) with a closer distance of metal atoms, a larger proportion of metal elements, and transition metal elements (Fe, Mn, and Co) leads to high thermal conductivity. To generally quantify the influence of such factors on thermal conductivity, the pathway factors with SBU influence () were proposed and can be used to efficiently classify structures into high, medium, and low thermal conductivity types. It was found that indicates that MOFs with topology tend to have high thermal conductivity, while and topologies naturally tend to possess medium and low thermal conductivity. Moreover, it was also suggested that taking as a descriptor in the machine learning algorithms can significantly improve the prediction accuracy for thermal conductivity. This study offers molecular insight into the impact of various SBUs on thermal conductivity in framework-based nanomaterials, which may guide the rational design of nanoporous materials with desirable thermal conductivity.
金属有机框架材料(MOFs)的热导率因其在能源相关领域的潜在应用而受到越来越多的关注。然而,由于构建单元的多样性,理解MOF结构与其热导率之间的关系仍然是一项紧迫的挑战。在本研究中,我们使用平衡分子动力学(EMD)模拟预测了MOFs的热导率(),并研究了结构性质对其热导率的贡献。结果表明,二级构建单元(SBUs)中金属原子距离更近、金属元素比例更大以及过渡金属元素(Fe、Mn和Co)的排列会导致高热导率。为了普遍量化这些因素对热导率的影响,提出了具有SBU影响的路径因子(),可用于有效地将结构分为高、中、低导热率类型。研究发现,表明具有拓扑结构的MOFs往往具有高热导率,而和拓扑结构自然倾向于具有中等和低导热率。此外,还建议在机器学习算法中以作为描述符可以显著提高热导率的预测准确性。本研究提供了关于各种SBUs对基于框架的纳米材料热导率影响的分子见解,这可能指导具有理想热导率的纳米多孔材料的合理设计。