Construction of MoS2 composite membranes on ceramic hollow fibers for efficient water desalination

Molybdenum disulfide (MoS2), as a promising two-dimensional (2D) material, has become an alternative membrane material for desalination due to its molecular and ionic sieving properties. Here we report a construction of a positively charged MoS2 composite membrane on a ceramic hollow fiber (CHF). A TiO2 interlayer was prepared in advance to narrow the pore size and smoothen the surface of the CHF. Polyethyleneimine (PEI) was incorporated to enhance the interfacial adhesion between adjoining MoS2 sheets, as well as the MoS2 layer and the substrate, thus facilitating the formation of a tightly-and neatly-packed separation layer. Besides, PEI endowed the composite membrane with positively charged and hydrophilic surface. The structures and properties of these membranes were investigated by scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and water contact angle (WCA) measurement. The obtained MoS2/PEI composite membrane displayed an outstanding nanofiltration (NF) performance with superior stability. Our study provided an in-depth understanding for the fabrication of MoS2 composite membrane on the CHF for efficient water desalination.