Nanofluid reverse electrodialysis (RED) is considered the most promising technology for harvesting osmotic energy. As materials used for RED, natural nanofluid materials are renewable but suffer from low power densities due to weak surface charge densities or irregular ion transport channels, while advanced materials from sophisticated manufacturing are too expensive. Here, a pair of novel natural nanofluid membranes with channel-like nanopores for highly improved selective ion transport were developed by assembling negatively and positively charged bacterial cellulose nanofibers via a space-confined flattened extrusion process. The regular internal channel-like nanopores with strongly increased surface charges assured less electrical imperfectness and therefore high ion selectivity, leading to RED systems with a high output power density of 0.72 W m⁻² (5.58 W m⁻² of negatively charged membranes), far superior to other existing natural nanofluidic RED systems. This strategy of efficiently enhancing the selective ion transport will open up a new route for the development of nanofluid RED devices, and allows a wide range of their applications in other energy fields.

纳米流体反向电渗析 (RED) 被认为是最有前途的获取渗透能的技术。作为用于 RED 的材料，天然纳米流体材料是可再生的，但由于表面电荷密度弱或离子传输通道不规则而导致功率密度低，而来自复杂制造的先进材料过于昂贵。在这里，通过空间受限的扁平挤出工艺组装带负电荷和正电荷的细菌纤维素纳米纤维，开发了一对具有通道状纳米孔的新型天然纳米流体膜，用于高度改善选择性离子传输。具有显着增加的表面电荷的规则内部通道状纳米孔确保了较少的电气缺陷，因此具有高离子选择性，导致 RED 系统具有 0.72 的高输出功率密度 W  m ^-2（5.58  W  m ^-2的负电荷膜），远远优于其他现有的天然纳米流体 RED 系统。这种有效增强选择性离子传输的策略将为纳米流体RED器件的开发开辟一条新途径，并使其在其他能源领域得到广泛的应用。