College of Chemistry and Environmental Science , Hebei University , Baoding 071002 , China.
State Key Laboratory of Separation Membranes and Membrane Processes , Tianjin Polytechnic University , Tianjin 300387 , China.
ACS Appl Mater Interfaces. 2019 Dec 11;11(49):46251-46260. doi: 10.1021/acsami.9b18018. Epub 2019 Nov 27.
Graphene oxide (GO) with a two-dimensional lamellar structure and single-atom thickness has exhibited advantages in water purification by stacking to a continuous membrane. However, a proper method to further increase the separation property of the GO membrane is still urgently needed. Besides, damage to the membrane during the full-scale application processes and the resulted consequential loss are prevalent problems need to be solved. Here, a hierarchically assembled GO composite membrane was developed that can achieve high-efficiency water purification performance and self-healing property via the synergistic effect of the metal-organic framework (MOF) and the coated hydrophilic layer of chitosan. The intercalated MOF effectively expanded the channel space of GO and endowed the channels with molecular-sieving property. Meanwhile, the coated chitosan layer can selectively adsorb water and achieve self-healing through the cross-linking reaction. The prepared GO composite membrane shows largely improved water flux (14.62 L m h bar), increased 344% than the water flux of the GO membrane, high rejection ratio (>99% for dyes), and good antifouling performance. In addition, the damaged GO composite membrane can recover its water flux (95%) and rejection ratio (96%) through a facile self-healing process.
氧化石墨烯（GO）具有二维层状结构和单层原子厚度，通过堆叠形成连续膜，在水净化方面表现出优势。然而，仍迫切需要一种适当的方法来进一步提高 GO 膜的分离性能。此外，在全规模应用过程中对膜的破坏以及由此产生的损失是普遍存在的问题，需要加以解决。在这里，通过金属-有机骨架（MOF）和壳聚糖涂层亲水区的协同作用，开发了一种分层组装的 GO 复合膜，可通过协同作用实现高效率的水净化性能和自修复性能。插层 MOF 有效地扩展了 GO 的通道空间，并赋予通道分子筛性能。同时，涂覆的壳聚糖层可以通过交联反应选择性地吸附水并实现自修复。所制备的 GO 复合膜表现出大幅提高的水通量（14.62 L m h bar），比 GO 膜的水通量提高了 344%，对染料的截留率>99%，具有良好的抗污染性能。此外，通过简单的自修复过程，受损的 GO 复合膜可以恢复其水通量（95%）和截留率（96%）。
