Stable porous graphene oxide membranes enabled by confined growth of 2D MOF nanosheets for high-performance desalination.

Graphene oxide (GO) membranes hold substantial promise for this application but are limited by structural instability in aqueous environments. This study introduces a composite membrane based on porous graphene oxide (PGO) with two-dimensional copper 1,4-benzenedicarboxylate (CuBDC) nanosheets grown in situ. The confined growth of CuBDC within the PGO laminar structure, via strong coordination between Cu2+ ions and oxygen-containing groups on PGO, not only stabilizes the PGO laminar structure but also induces NaCl rejection due to the appropriate pore size of the CuBDC. The resulting composite membrane demonstrated a high-water flux of 124 kg m-2 hour-1 in conventional pervaporation and 89 kg m-2 hour-1 in low-energy water carrier pervaporation, with NaCl rejection consistently above 99.9%. Technoeconomic analysis reveals that desalination using the fabricated membrane in a water-carrier pervaporation process results in a low annual expenditure. Overall, this study offers a promising strategy for stabilizing PGO membranes with excellent selectivity, paving the way for more energy-efficient desalination technologies.