The electronic properties and water desalination performance of a photocatalytic TiO 2 /MoS 2 nanocomposites bilayer membrane: a molecular dynamic simulation.

Due to the rapid depletion of water resources, more interest is paid for the efficient desalination process in recent years. MoS 2 membrane aroused attention due to its high mechanical stability and electronic properties, which can sustain extra-large strains. In this study, the electronic properties and water desalination performance of TiO 2 /MoS 2 -hexagonal, and TiO 2 /MoS 2 -rhombohedral nanocomposites bilayer membranes were studied and simulated for the first time. The effect of TiO 2 in the performance of MoS 2 was observed in water desalination under the defined applied pressure ranging from 50 to 250 MPa with a 6.4 Å pore diameter. The membrane structure is created and optimized. The energy minimized for TiO 2 from - 19,596.4282 kcal/mol for the initial structure to - 19,605.1611 kcal/mol for the final structure. For TiO 2 /MoS 2 -hexagonal, the energy minimized from - 4955.54271 eV) to - 4955.62091 eV and TiO 2 /MoS 2 -rhombohedral from - 6042.26925 eV to - 6046.91835 eV. A molecular dynamic (MD) simulation was performed using Material Studio 2019 to study the electronic properties under 0-1 eV electric field using the CASTEP code. The results showed a better photocatalytic performance under the external electric field. The effect of external electric field significantly intensifies absorption in the visible range and achieved a high photocatalytic activity on TiO 2 /MoS 2 . TiO 2 , TiO 2 /MoS 2 -hexagonal and TiO 2 /MoS 2 -rhombohedral nanocomposites bilayer membranes are simulated and evaluated for the water desalination using ReaxFF software. Both MoS 2 phases with TiO 2 have achieved a high salt rejection up to 97% (P-value = 0.0036, R 2  = 0.958), while TiO 2 /MoS 2 -rhombohedral achieved the highest permeability (6.0*10 -8  mm g cm -2  s -1  bar -1 ) (P-value = 0.000296, R 2  = 0.972) under 250 MPa applied pressure.