The reverse osmosis (RO) desalination technology is an alternative approach to relieve the worldwide freshwater shortage. However, this technology currently suffers from low efficiency. Developing a highly efficient RO membrane is thus pivotal to expedite the further progress of RO technology. Herein using in silico approach, we demonstrate the efficient desalination performance of carbon nitride (C₃N) nanoslits. The water permeation across the slits depends on the slit spacing. Particularly, the water permeability through 6 Å spacing achieves an ideal value of about 15 L/cm²/day/MPa accompanied by the complete salt rejection. The enlarged spacings increase the water permeability. These water permeability is much higher than the conventional commercial membranes with two orders of magnitude improvement, indicating that the C₃N nanoslits are superior for desalination. The local analysis presents that the incremental slit enables more waters to penetrate. The free energy calculations further confirm that the considerable water permeation is attributed to the lower free energy barrier for water passing through the slit than ions. Our findings demonstrate that the C₃N nanoslits can be exploited as a desired RO membrane for efficient freshwater acquirement, which is beneficial for future design of filtration membrane.

反渗透 (RO) 海水淡化技术是缓解全球淡水短缺的替代方法。然而，该技术目前存在效率低下的问题。因此，开发高效的反渗透膜对于加快反渗透技术的进一步发展至关重要。在此使用计算机方法，我们展示了氮化碳 (C ₃ N) 纳米狭缝的有效脱盐性能。穿过狭缝的水渗透取决于狭缝间距。特别是通过 6 Å 间距的透水率达到约 15 L/cm ^{2的理想值}/天/兆帕伴随着完全的脱盐。扩大的间距增加了水的渗透性。这些透水性远高于传统的商业膜，提高了两个数量级，表明 C ₃ N 纳米狭缝在脱盐方面具有优势。局部分析表明，增量狭缝使更多的水能够渗透。自由能计算进一步证实，相当大的水渗透归因于水通过狭缝的自由能垒比离子低。我们的研究结果表明，C ₃ N 纳米狭缝可以作为理想的反渗透膜用于有效的淡水获取，这有利于未来过滤膜的设计。