Reasons behind superior water desalination performance of nanoporous MoS$_{\mathrm{2}}$

Water desalination is one of the most prevailing technologies to solve freshwater scarcity nowadays. Membranes made of two-dimensional (2D) materials such as single-layer MoS$_{\mathrm{2}}$ and Graphene have been demonstrated to be able to significantly increase the water desalination performance. In this work, we made thorough comparison between popular 2D materials including MoS$_{\mathrm{2}}$, MoSe$_{\mathrm{2}}$, Graphene, Boron Nitride, and Phosphorene and conclude that MoS$_{\mathrm{2}}$ constantly performs 20{\%} - 38{\%} better than the others. We further revealed the reasons of the superior performance of MoS$_{\mathrm{2}}$ from the perspective of water dynamics and structure near the membrane/inside the pores, and the energy barrier for water molecules to transport through the pore.