1.D.198. The Mxene-Graphine oxide Membrane (MGOm) Family
Two-dimensional MXenes have become a crucial topic in the field of ion transport, owing to their excellent electrochemical performance. Ouyang et al. 2022 presented a strategy for preparing a layered MXene-graphene oxide (GO) membrane via vacuum filtration, which endows the delaminated two-dimensional MXene-GO membrane (MGOm) with excellent electrical conductivity and chemical stability, achieving voltage-gated ion transport behavior. Owing to the presence of charges or dipoles within the membrane's channel, the movement of electrons or dipoles under the influence of a membrane potential is possible. By varying the transmembrane potential, the transition between the closed and open states of the voltage-gated ion channel can be adjusted. When a negative potential is applied at osmotic pressure, the force between the charged MGOm sheet and the cation (K+) is enhanced, promoting ion permeation. Conversely, the application of a positive potential attenuates electrostatic attraction, resulting in a decrease in ion permeability. In addition, the effects of MXene and GO with different modulation ratios on the voltage-gated ion transport have shown that when the modulation ratio of MXene : GO is 7 : 3, the optimal ion permeation rate is achieved. Thus, the conductive film with voltage-gated nanochannels is a promising alternative for ion transport, opening up new avenues for the further exploration of MXene materials in energy storage devices (Ouyang et al. 2022).