1. Understanding the Aqueous Stability and Filtration Capability of MoS2 Membranes
- Author
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Baoxia Mi, Qingsong Tu, Zhongying Wang, Shaofan Li, Sunxiang Zheng, and Jeffrey J. Urban
- Subjects
Ionic bonding ,Bioengineering ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Membrane technology ,law.invention ,symbols.namesake ,chemistry.chemical_compound ,law ,General Materials Science ,Molybdenum disulfide ,Filtration ,Nanosheet ,Aqueous solution ,Mechanical Engineering ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Membrane ,chemistry ,Chemical engineering ,symbols ,van der Waals force ,0210 nano-technology - Abstract
Membranes made of layer-stacked two-dimensional molybdenum disulfide (MoS2) nanosheets have recently shown great promise for water filtration. At present, the reported water fluxes vary significantly, while the accountable structure and properties of MoS2 nanochannels are largely unknown. This paper aims to mechanistically relate the performance of MoS2 membranes to the size of their nanochannels in different hydration states. We discovered that fully hydrated MoS2 membranes retained a 1.2 nm interlayer spacing (or 0.9 nm free spacing), leading to high water permeability and moderate-to-high ionic and molecular rejection. In comparison, completely dry MoS2 membranes had a 0.62 nm interlayer spacing (or 0.3 nm free spacing) due to irreversible nanosheet restacking and were almost impermeable to water. Furthermore, we revealed that the interlayer spacing of MoS2 membranes in aqueous solution is maintained by comparable van der Waals and hydration forces, thereby ensuring the aqueous stability of MoS2 membra...
- Published
- 2017