Graphene oxide (GO) membranes have been proved to be ion-selective thanks to their oxidized functional groups, which are naturally present on its surface. This ion selectivity, together with good mechanical strength, low cost, and simple synthesis, makes GO a great alternative material to conventional costly polymers for the production of ion-exchange membranes. This work focuses on how to produce GO membranes as ion-exchange membranes with a scalable approach and tunable permselectivity. Their physicochemical properties were subsequently investigated by means of selected characterization techniques. Results showed that GO membranes present good ion selectivity and size exclusion towards monovalent cations, reaching a permselectivity of up to 96%. Interestingly, UV-light irradiation of GO membranes can also be proposed as a green reduction method. GO reduction increases the permselectivity due to both a decrease in the dimension of the nanochannels and a reduction in the swelling degree of the membranes. The addition of binders was also investigated to improve the membranes’ mechanical properties. Finally, the ionic resistance of the membranes was measured by impedance spectroscopy, achieving 4.6 Ω cm², orders of magnitude lower than the state-of-the-art graphene oxide-based membranes.

氧化石墨烯（GO）膜已被证明具有离子选择性，这要归功于其表面天然存在的氧化官能团。这种离子选择性，加上良好的机械强度、低成本和简单的合成，使 GO 成为生产离子交换膜的传统昂贵聚合物的绝佳替代材料。这项工作的重点是如何通过可扩展的方法和可调的选择性渗透性来生产 GO 膜作为离子交换膜。随后通过选定的表征技术研究了它们的物理化学性质。结果表明，GO 膜对单价阳离子具有良好的离子选择性和尺寸排阻性，选择性渗透率高达 96%。有趣的是，GO 膜的紫外光照射也可以作为一种绿色还原方法。由于纳米通道尺寸的减小和膜膨胀程度的降低，GO 的减少增加了选择性渗透性。还研究了添加粘合剂以提高膜的机械性能。最后，通过阻抗谱测量膜的离子电阻，达到4.6 Ω cm^如图2所示，比最先进的基于氧化石墨烯的膜低几个数量级。