High-performance osmotic energy conversion (OEC) requires both high ionic selectivity and permeability in nanopores. Here, through systematical explorations of influences from individual charged nanopore surfaces on the performance of OEC, we find that the charged exterior surface on the low-concentration side (surface_L) is essential to achieve high-performance osmotic power generation, which can significantly improve the ionic selectivity and permeability simultaneously. Detailed investigation of ionic transport indicates that electric double layers near charged surfaces provide high-speed passages for counterions. The charged surface_L enhances cation diffusion through enlarging the effective diffusive area, and inhibits anion transport by electrostatic repulsion. Different areas of charged exterior surfaces have been considered to mimic membranes with different porosities in practical applications. Through adjusting the width of the charged ring region on the surface_L, electric power in single nanopores increases from 0.3 to 3.4 pW with a plateau at the width of ~200 nm. The power density increases from 4200 to 4900 W/m² and then decreases monotonously that reaches the commercial benchmark at the charged width of ~480 nm. While, energy conversion efficiency can be promoted from 4% to 26%. Our results provide useful guide in the design of nanoporous membranes for high-performance osmotic energy harvesting.

高性能渗透能转换（OEC）需要高离子选择性和纳米孔渗透性。在这里，通过系统地研究各个带电纳米孔表面对OEC性能的影响，我们发现低浓度侧（表面_L）的带电外表面对于实现高性能渗透发电至关重要，这可以显着提高同时具有离子选择性和渗透性 离子迁移的详细研究表明，带电表面附近的双电层为抗衡离子提供了高速通道。带电面_L通过扩大有效扩散面积来增强阳离子扩散，并通过静电排斥抑制阴离子迁移。在实际应用中，已经考虑了带电外表面的不同区域来模拟具有不同孔隙率的膜。通过调节表面_L上带电环区域的宽度，单个纳米孔中的功率从0.3 pW增加到3.4 pW，并在〜200 nm的宽度处达到平稳。功率密度从4200 W / m ²增加到4900 W / m ²，然后在〜480 nm的充电宽度下单调降低，达到商业基准。同时，能量转换效率可以从4％提高到26％。我们的结果为设计用于高性能渗透能的纳米多孔膜提供了有用的指导。