Two-dimensional graphitic carbon nitride (g-C₃N₄) nanosheets are ideal candidates for membranes because of their intrinsic in-plane nanopores. However, non-selective defects formed by traditional top-down preparation and the unfavorable re-stacking hinder the application of these nanosheets in gas separation. Herein, we report lamellar g-C₃N₄ nanosheets as gas separation membranes with a disordered layer-stacking structure based on high quality g-C₃N₄ nanosheets through bottom-up synthesis. Thanks to fast and highly selective transport through the high-density sieving channels and the interlayer paths, the membranes, superior to state-of-the-art ones, exhibit high H₂ permeance of 1.3 × 10⁻⁶mol m⁻² s⁻¹ Pa⁻¹ with excellent selectivity for multiple gas mixtures. Notably, these membranes show excellent stability under harsh practice-relevant environments, such as temperature swings, wet atmosphere and long-term operation of more than 200 days. Therefore, such lamellar membranes with high quality g-C₃N₄ nanosheets hold great promise for gas separation applications.

二维石墨氮化碳 (gC ₃ N ₄ ) 纳米片因其固有的面内纳米孔而成为膜的理想候选者。然而，传统自上而下制备形成的非选择性缺陷和不利的重新堆叠阻碍了这些纳米片在气体分离中的应用。在此，我们报道了层状gC ₃ N ₄纳米片作为气体分离膜，其具有基于自下而上合成的高质量gC ₃ N _{4纳米片的无序层堆叠结构。}由于通过高密度筛分通道和层间路径的快速和高度选择性传输，该膜优于最先进的膜，表现出高 H ₂1.3 × 10 ^-6 mol m ^-2  s ^-1  Pa ^-1的渗透性，对多种气体混合物具有出色的选择性。值得注意的是，这些膜在与实践相关的恶劣环境下表现出出色的稳定性，例如温度波动、潮湿大气和超过 200 天的长期运行。因此，这种具有高质量gC ₃ N ₄纳米片的层状膜在气体分离应用中具有很大的前景。