Comparison of water desalination performance of porous graphene and MoS 2 nanosheets.

Following graphene and its derivatives, molybdenum disulfide (MoS 2 ) has become a research hotspot in two-dimensional materials. Both graphene and MoS 2 exhibit great potential in water treatment. A variety of nanoporous graphene or MoS 2 membranes have been designed for water desalination. In this work, we compared the water flux and ion rejection of MoS 2 and graphene nanopores, using molecular dynamics simulations. The simulation results demonstrate that monolayer nanopores have higher water fluxes than bilayer nanopores with lower ion rejection rates. MoS 2 nanopores perform better than graphene in terms of water permeability. Exploration of the underlying mechanism indicates that the water molecules in the MoS 2 pores have faster velocity and higher mass density than those in the graphene pores, due to the outer hydrophobic and inner hydrophilic edges of MoS 2 pores. In addition, increasing the polarity of the pore edge causes a decrease in water flux while enhancement of ion rejection. Our findings may provide theoretical guidance for the design of MoS 2 membranes in water purification.