Nanofiltration (NF) technology has been widely used in saline wastewater treatment due to its unique separation mechanism. However, the NF membrane, as the core of the nanofiltration technology, is restricted by the trade-off between permeability and selectivity, which greatly restricts the development of NF membranes. The interlamellar arrangement of 2D boron nitride nanosheets (BNNSs) can provide additional transport channels and selectivity, as well as strong adsorption capacity due to its high specific surface area, exhibiting significant potential for advanced membranes. In this work, BNNSs prepared by tannic acid (TA)-assisted exfoliation (TA@BNNSs) were successfully adopted to fabricate thin-film nanocomposite (TFN) membranes via interfacial polymerization (IP). The resultant TFN membranes’ structure and properties were systematically characterized via various methods. The results demonstrated that the surface morphology of polyamide membranes evolved gradually from a nodular structure to a reticular topography, accompanied by the decrease of the thickness of the polyamide selective layer when incorporating TA@BNNSs into the membranes. This phenomenon can be mainly ascribed to that the uptake density and diffusion of piperazine (PIP) monomer were effectively regulated by BNNSs. This is validated by molecular dynamics and revealed by the adsorption of PIP in BN models, the diffusion coefficients, and interaction energies, respectively. In addition, the TFN membranes demonstrated improved permeance and stable solute rejection for the inorganic salts. Specifically, the water flux of PA-TA@BNNSs-10%/PMIA membrane could reach up to 109.1 ± 2.49 L·m–2·h–1 while keeping a high rejection of 97.5 ± 0.38% to Na2SO4, which was superior to most of the reported membranes in the literature. Besides, the PA-TA@BNNSs-10%/PMIA membrane exhibited an excellent stability in the long-term filtration process. The finding in this work provides a potential strategy for developing the next-generation 2D material-based membranes with high-performance for separation applications.

Metal–phenolic networks (MPNs) are novel supramolecular materials with numerous applications in the field of advanced material science and engineering due to their plentiful fascinating features. Following the first assembling of MPN films on diverse solid surfaces in 2013, MPN materials have attracted much attention in the membrane technology field to improve membrane multifunctionality through membrane surface or matrix modification for membrane structural stability, durability, and filtration efficiency enhancements. Moreover, the incorporation of inorganic nanomaterials, such as nanoparticles, nanotubes, nanorods, and nanosheets, and hydrophilic polymers, for instance, zwitterions and polyvinylpyrrolidone (PVP), can enable further improvements of MPN-based membranes for diverse water filtration applications. This review has critically summarized the recent MPN-based membrane modifications and identified areas that need to be considered in further research to enhance membrane durability, filtration performance, and operational lifetime. Overall, it is foreseen that the novel membranes, as well as an ever-widening scope of membrane applications based on the MPN material, will constantly emerge.