Construction of a Two-Dimensional GO/Ti3C2TX Composite Membrane and Investigation of Mg2+/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/Ti3C2TX2D composite membranes with 2D/2D structures by intercalating Ti3C2TXnanosheets with slightly smaller sizes into GO membranes. Ti3C2TXintercalation 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/Ti3C2TXcomposite membrane exhibited a good Mg2+/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 Ti3C2TXnanosheets significantly improved the stability of GO/Ti3C2TXmembranes in different pH environments. This study provides a unique insight into the preparation of highly permeable and ion-selective GO membranes.Keywords:graphene oxide;Ti3C2TXnanosheets;two-dimensional materials membrane;Mg2+/Li+separation