Abstract:
Nanofluidic channels in a membrane represent a promising avenue for harnessing blue energy from salinity gradients, relying on permselectivity as a pivotal characteristic crucial for inducing electricity through diffusive ion transport. Surface charge emerges as a central player in the osmotic energy conversion process, emphasizing the critical significance of a judicious selection of membrane materials to achieve optimal ion permeability and selectivity within specific channel dimensions. Alternatively, here we report a field-effect approach for in situ manipulation of the ion selectivity in a nanopore. Application of voltage to a surround-gate electrode allows precise adjustment of the surface charge density at the pore wall. Leveraging the gating control, we demonstrate permselectivity turnover to enhanced cation selective transport in multipore membranes, resulting in a 6-fold increase in the energy conversion efficiency with a power density of 15 W/m2 under a salinity gradient. These findings not only advance our fundamental understanding of ion transport in nanochannels but also provide a scalable and efficient strategy for nanoporous membrane osmotic power generation.
摘要:
膜中的纳米流体通道代表了利用盐度梯度中的蓝色能量的有希望的途径,依赖于选择通过扩散离子传输诱导电的关键特性。表面电荷在渗透能量转换过程中作为中心角色出现,强调明智选择膜材料以在特定通道尺寸内获得最佳离子渗透性和选择性的关键意义。或者,在这里,我们报告了一种场效应方法,用于原位操纵纳米孔中的离子选择性。向环绕栅电极施加电压允许精确调节孔壁处的表面电荷密度。利用门控控制,我们证明了在多孔膜中选择性转化为增强的阳离子选择性转运,在盐度梯度下,功率密度为15W/m2时,能量转换效率提高了6倍。这些发现不仅促进了我们对纳米通道中离子传输的基本理解,而且为纳米多孔膜渗透发电提供了可扩展且有效的策略。