Thin-film nanocomposite membrane incorporated by aminated MoS₂ nanodots for Cl^-/SO₄^2- separation

Interfacial polymerization is the most preferred method to fabricate nanofiltration and reverse osmosis membranes in both academia and industry, while it is facing the challenge of high performance, especially in flux. Herein, we proposed a method to incorporate the amino-functionalized molybdenum disulfide (MoS₂–N) nanodots (NDs) in interfacial polymerization to tune the membrane structure, especially the water transport path to enhance membrane performance. MoS₂ NDs have characteristics of high surface smoothness and low fluid diffusion resistance. The MoS₂ NDs incorporated thin-film nanocomposite (TFN) membrane can reduce the water friction resistance in membrane matrix, thus accelerating the transmembrane transfer of water molecules. The morphology and properties of the NDs and membranes were characterized. The functionalization degree and concentration of MoS₂–N NDs in the membrane were tuned. At optimum conditions, the MoS₂–N NDs incorporated TFN membrane exhibited a pure water permeance of 24.98 LMH/bar, 2.5-fold that of the control membrane, with a high Cl^-/SO₄^2- selectivity of 119.2 (NaCl and Na₂SO₄) and a good long-term stability.