Ultrathin two-dimensional MXene membrane for pervaporation desalination

As a new family of two-dimensional (2D) materials, MXene, with many attractive physicochemical properties, has attracted increasing attentions and been applied for various applications. Here, for the first time, ultrathin MXene membranes with thickness down to several tens of nanometers were developed for pervaporation desalination by stacking synthesized atomic-thin MXene nanosheets. Influences such as lateral size of MXene nanosheets and feed temperature on the resulting membrane performance were systematically investigated. Owing to unique 2D interlayer channels as well as high hydrophilicity, the ultrathin MXene membrane with ~60 nm exhibited high water flux (85.4 L m⁻² h⁻¹) and salt rejection (99.5%) with feed concentration of 3.5 wt% NaCl at 65 °C. In addition, the MXene membrane showed a good long-term stability and performance in synthetic seawater system. The high-performing ultrathin 2D MXene membrane developed here in this work offers great potential for pervaporation applications.