Supramolecular Calix[n]arenes-Intercalated Graphene Oxide Membranes for Efficient Proton Conduction

Graphene oxide (GO) membranes with 2D interlaminar channels have triggered intensive interest as ion conductors. Incorporating abundant ion-conducting sites into GO interlayers is recognized as an effective strategy to facilitate ion conduction. Herein, we designed supramolecular compounds, para-sulphonato-calix[n]arenes (p-SC[n]As), as versatile intercalators to acquire highly conductive and robust GO membranes. The SC[n]A with ultrahigh ionic exchange capacity (IECw, 5.37 mmol g-1) imparts sufficient proton donors, and its rigid framework imparts strong support of adjacent nanosheets. We designed three kinds of SC[n]As with the same IECw but different sizes as intercalators, endowing the GO/SC[n]A membranes with increasing ion concentration and d-spacing in the order of GO/SC[4]A < GO/SC[6]A < GO/SC[8]A. Therefore, the interlayers of GO/SC[8]A membranes afforded higher density of proton donors and could accommodate more water molecules to construct more continuous H-bond networks for proton transfer. Ac...