二维纳米孔道中盐溶液微观结构与离子输运调控的分子模拟研究

近年新兴的二维纳米孔道（简称2D孔道）内盐溶液与孔道壁作用强烈，产生特定溶液微观结构，对离子输运影响显著（限域效应、入口效应等），若能合理调控可广泛应用于盐差发电、超级电容、海水淡化、离子筛分等领域。为设计高性能2D孔道，亟需通过分子模拟理解其输运机理；但目前模拟力场仍不够准确，输运机理阐释尚不深入。针对这些问题，本项目拟以密度泛函理论（DFT）计算为基础，开发可准确模拟溶液中离子-2D孔道相互作用的力场；继而在分子动力学（MD）模拟中通过分析离子受力、能量等阐明孔道中溶液微观结构调控离子输运的机理，还将探究孔道材料、结构、外场甚至不同力场参数等模拟变量对离子输运的影响机制；从中提炼深刻、普适的2D孔道离子输运规律（如同体相盐溶液的Stokes-Einstein、Modified Debye-Huckel公式）。研究成果对2D孔道溶液离子输运研究有重要学术意义，可为其广泛应用奠定理论基础。

The emerging 2D nanochannels, built from 2D materials, have shown supre performance for applications such as super-capacitor, osmotic power generation, desalination and ion sieving etc. These could be attributed to that, the electrolyte solution in the nanochannels interact significantly with the channel walls (2D materials), which leads to certain solution microstructure and regulate the ion transportation, e.g. the confinement effect, entrance effect etc. It is critical to understand the aquoues ion transportation mechanism in 2D nanochannls with molecular simulation for designing 2D nanochannels with even higher performance. However, relevant studies are currently at the very begining stage, and a range of challenges are hindering their development: improving the accuracy of the employed force fields; studying systematically and thoroughly; particurlly, universal and powerful scientific rules are very scarce, etc. This project will develop force field based on density functional theory (DFT) calculations, which could accurately simulate the ion-2D material interactions in aqueous solution. It will simulate ion transportation in various 2D nanochannels by systematically varying the variable of the simulation systems: the 2D materials, the height of the nanochannel, the external field, and even employing different ion force fields. The project will elucidate how the 2D nanochannels regulate the ion transportation via the micro-structure of the electrolyte solutions. Furthermore, it will derive in-depth, universal and powerful equations for ion transportation in 2D nanochannels (think about the Stokes-Einstein, Modified Debye-Huckel equations for bulk electrolyte solutions). The results and insights gained from this project is of vital scientific significance for studying the aquoues ion transportation in 2D nanochannels, also will pave the way for the wide applications of 2D nanochannels.