Structure and Pore Size Distribution in Nanoporous Carbon
Structure and Pore Size Distribution in Nanoporous Carbon
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DOI：
10.1021/acs.chemmater.1c03279
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发表时间：
2022-01-04
影响因子：
8.6
通讯作者：
Caro, Miguel A.
中科院分区：
文献类型：
--
作者：
Wang, Yanzhou;Fan, Zheyong;Caro, Miguel A.
我们通过原子机器学习（ML）驱动的分子动力学（MD）模拟研究了纳米多孔（NP）碳材料的结构和力学性能。为此，我们通过重新计算Deringer和Csanyi的a-C结构数据库添加货车德瓦尔斯相互作用来重新训练碳的ML高斯近似势（GAP）。我们的GAP实现了显著的加速，并提高了能量和力预测的准确性。我们使用差距来深入研究计算NP碳样品中的原子结构和孔径分布。这些样品是通过熔融石墨化淬火MD程序在宽范围的密度（从0.5到1.7 g/cm（3））与结构包含131 072个原子。我们的研究结果是在良好的协议与可用的观测数据的实验数据，并提供了一个全面的帐户的结构（径向和角分布函数，图案和环计数，X射线衍射图案，孔表征）和机械（弹性模量及其随密度的演变）性能。我们的研究结果表明，相对较窄的孔径分布，其中的峰值位置和宽度的分布是由材料的质量密度。我们的数据允许NP碳材料的计算表征的进一步工作，特别是用于储能应用，以及建议NP碳基材料的未来实验表征。
We study the structural and mechanical properties of nanoporous (NP) carbon materials by extensive atomistic machine-learning (ML) driven molecular dynamics (MD) simulations. To this end, we retrain a ML Gaussian approximation potential (GAP) for carbon by recalculating the a-C structural database of Deringer and Csanyi adding van der Waals interactions. Our GAP enables a notable speedup and improves the accuracy of energy and force predictions. We use the GAP to thoroughly study the atomistic structure and pore-size distribution in computational NP carbon samples. These samples are generated by a melt-graphitization-quench MD procedure over a wide range of densities (from 0.5 to 1.7 g/cm(3)) with structures containing 131 072 atoms. Our results are in good agreement with experimental data for the available observables and provide a comprehensive account of structural (radial and angular distribution functions, motif and ring counts, X-ray diffraction patterns, pore characterization) and mechanical (elastic moduli and their evolution with density) properties. Our results show relatively narrow pore-size distributions, where the peak position and width of the distributions are dictated by the mass density of the materials. Our data allow further work on computational characterization of NP carbon materials, in particular for energy-storage applications, as well as suggest future experimental characterization of NP carbon-based materials.