Construction of a Two-Dimensional GO/Ti(3)C(2)T(X) Composite Membrane and Investigation of Mg(2+)/Li(+) Separation Performance

Graphene oxide (GO) two-dimensional (2D) membranes with unique layer structures and tunable layer spacing have special advantages and great potential in the field of water treatment. However, GO membranes face the issues of weak anti-swelling ability as well as poor permeability. We prepared GO/Ti(3)C(2)T(X) 2D composite membranes with 2D/2D structures by intercalating Ti(3)C(2)T(X) nanosheets with slightly smaller sizes into GO membranes. Ti(3)C(2)T(X) intercalation can effectively expand the layer spacing of GO, thereby substantially enhancing the flux of the composite membrane (2.82 to 6.35 L·m(−2)·h(−1)). Moreover, the GO/Ti(3)C(2)T(X) composite membrane exhibited a good Mg(2+)/Li(+) separation capability. For the simulated brine, the separation factor of M2 was 3.81, and the salt solution flux was as high as 5.26 L·m(−2)·h(−1). Meanwhile, the incorporation of Ti(3)C(2)T(X) nanosheets significantly improved the stability of GO/Ti(3)C(2)T(X) membranes in different pH environments. This study provides a unique insight into the preparation of highly permeable and ion-selective GO membranes.