Bioinspired Redox-Responsive Graphene Oxide Membrane Based on Supramolecular Host-Guest Interaction for Tunable Molecular Separation

Intelligent and controllable water and molecule transport through a membrane is of crucial significance for broadening membrane applications in smart-gating filtration. Herein, inspired by the extensive redox reactions in living systems, we report a redox-responsive graphene oxide (GO) membrane assembled by introducing a supramolecular host-guest complex between ferrocene (Fc) and beta-cyclodextrin (CD) into the interlayer of GO. The well-designed intelligent responsive membrane, which was composed of Fc-modified GO and CD-modified GO, possessed fascinating redox-response property. Utilizing the reversible deformation and restoration of the Fc/ CD complex, the size of the interlayer nanochannel between adjacent GO nanosheets was tunable by changing the membrane redox state. The water permeance and molecular separation performance of the membrane could be reversibly regulated with a high gating ratio (5.6) by virtue of the redox-responsive interlayer nanochannel. In addition, the obtained membrane also demonstrated superior cyclic response performance, excellent antifouling ability, and satisfactory stability in harsh environments. This work provides an innovative strategy for the fabrication of redox-responsive membranes, showing promising applications in intelligent and controllable gating and controllable water-contaminant removal process.