MoS2-based membranes in water treatment and purification

Membrane separation technologies have proven viable in tackling the issues of water pollution and shortage of freshwater resources with practical applications. Two-dimensional (2D) materials with thickness of one to a few atoms stand out as desirable building blocks to design and fabricate membranes with outstanding performances. Molybdenum disulfide (MoS), as a promising alternative 2D material, has been currently one of the most intriguing 2D materials beyond graphene due to many excellent physicochemical, mechanical and biological properties, which are not available in graphene-based nanomaterials. However, to the best of our knowledge, there has been few reviews of MoS-based membranes studies. It is thus urgently needed to summarize key findings of MoS-based membranes and assess the current research studies in this area. This paper attempts to critically review the present state-of-the-art of MoS-based membranes in water treatment and purification. Firstly, we briefly introduce the main preparation methods of MoS nanosheets, which are often applied in fabricating membranes. Next, the design and fabrication of MoS-based membranes are systematically summarized in terms of nanoporous membranes, layer-stacked membranes, MoS composite membranes including MoS-incorporated membranes, and membranes surface modification with MoS. Then, we critically review the recent advancement about applications of MoS-based membranes for water treatment and purification, focusing on desalination, industrial wastewater treatment, and antifouling properties. Finally, we discuss the existing challenges, future research efforts and opportunities of MoS-based membranes. This work will be very valuable to understand the current state-of-the-art of MoS-based membranes and will be helpful for developing other 2D-based membranes for efficient and low-energy-consumption in water treatment and purification.