Forward osmosis membranes modified with laminar MoS2 nanosheet to improve desalination performance and antifouling properties

Internal concentration polarization (ICP) and membrane fouling are factors limiting the performance of forward osmosis (FO) membranes. Aiming at alleviating these problems, this study demonstrated the fabrication of FO membrane incorporated with MoS2 by layer-by-layer assembly with the synergistic effects of surface hydrophilicity, porosity and fouling-release properties. The grafting of MoS2 on the membrane surface was confirmed through the SEM, EDS and AFM analysis. The results demonstrated that the MoS2-coated-FO membrane could achieve transmembrane water flux of 27.15 LMH which was 35.34% higher than that obtained from a commercial polyethersulfone (PES) FO membrane. The reverse flux of NaCI ions was 16.42 gMH for the MoS(2)coated-FO, 35.91% less than blank FO membrane. Meanwhile, coating MoS2 nanosheets endowed the resultant composites with higher water flux and lower reverse solute diffusion. In addition, the results of dynamic operation in a cross-flow test cell demonstrated that MoS2-coated-FO membrane exhibited good antifouling and fouling-release properties. This study indicates that use of MoS2 nanosheet is an attractive and feasible approach for the development of a dual-functional FO membrane by simultaneously improving the antifouling performance and reducing the ICP issues.