Bottom-Up Synthesisfor Defect-Free Two-DimensionalMoS₂ Sieving Membranes

Membranes have seen growing interest in employing 2D materials for water treatment and desalination, aiming to enhance the performance of the current technologies. Among these 2D materials, MoS₂ nanosheets have recently attracted significant attention. Current fabrication approaches of MoS₂-based membranes require intensive electrochemical or sonication steps, which may hinder scalability. Besides, top-down methods usually produce MoS₂ slabs with large size distributions, creating detrimental defects affecting selectivity. We present a single-step bottom-up MoS₂ synthesis that yields highly concentrated solutions containing exclusively MoS₂ single-layer nanosheets allowing a perfect laminar stacking on poly(ether sulfone) (PES) support leading to excellent monovalent salt rejection (99.7% ± 0.5 NaCl).