Wang Yuting, Chen Huaxiang, Zhai Jin
Key Laboratory of Smart Bioinspired Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing 100191, P. R. China.
China National Petroleum Corporation Energy East Road, Petrochemical Research Institute, Shahe Town, Changping District, Beijing 102200, P.R.China.
ACS Appl Mater Interfaces. 2021 Sep 1;13(34):41159-41168. doi: 10.1021/acsami.1c07972. Epub 2021 Aug 17.
As an important nanofluidic device, an artificial ion nanochannel could selectively transport ions inside its nanoconfinement space and the surface charge of the pore wall. Here, confinement effects were realized by tandem nanochannel units, which kept their cascade gaps less than 500 nm. Within these gaps, ionic conductance was governed by the surface charge density of the channel unit. Cations could be sufficiently selected and enriched within this confined space, which improves the cation transfer number of the system. Therefore, the tandem nanochannel system could greatly improve the diffusion potential and energy conversion efficiency in the salinity gradient power generation process. Poisson-Nernst-Planck equations were introduced to numerically simulate the ionic transport behavior and confirmed the experimental results. Finally, the gap confinement effect was introduced in the porous cellulose acetate membrane tandem nanochannel system, and a high output power density of 4.72 W/m and energy conversion efficiency of 42.22% were achieved under stacking seven channel units.
作为一种重要的纳米流体装置，人工离子纳米通道能够在其纳米受限空间和孔壁表面电荷内选择性地传输离子。在此，通过串联纳米通道单元实现了受限效应，这些单元的级联间隙保持在500纳米以下。在这些间隙内，离子电导由通道单元的表面电荷密度决定。阳离子能够在这个受限空间内得到充分的选择和富集，这提高了系统的阳离子迁移数。因此，串联纳米通道系统能够极大地提高盐度梯度发电过程中的扩散电位和能量转换效率。引入泊松-能斯特-普朗克方程对离子传输行为进行数值模拟，并证实了实验结果。最后，在多孔醋酸纤维素膜串联纳米通道系统中引入间隙受限效应，在堆叠七个通道单元的情况下，实现了4.72瓦/平方米的高输出功率密度和42.22%的能量转换效率。
