Low dimensional materials have been examined as electrocatalysts for the hydrogen evolution reaction (HER). Among them, two-dimensional Transition Metal Dichalcogenides (2D-TMDs) such as MoS 2 have been identified as potential candidates. However, the performance of TMDs towards HER in both acidic and basic media remains inferior to that of noble metals such as Pt and its alloys. This calls for investigating the influence of controlled defect engineering of 2D Hydrothermal synthesis 6.5ű0.04

Nanolaminate membranes made of two-dimensional materials (2D) such as graphene oxide (GO) are promising candidates for molecular sieving via size-limited diffusion in the 2D capillaries, but high hydrophilicity makes these membranes unstable in water. Here, we 25 report a nanolaminate membrane based on covalently functionalized molybdenum disulfide (MoS 2 ) nanosheets. The functionalized MoS 2 membranes demonstrate >90% and ~ 87% rejection for micropollutants and NaCl respectively when operating under reverse osmotic conditions. The sieving performance and water flux of the functionalized MoS 2 membranes are attributed to both control of the capillary widths of the nanolaminates and 30 control of the surface chemistry of the nanosheets. We identified small hydrophobic 20 12 References

Crystalline and amorphous transition-metal chalcogenides such as MoS2 are currently recognized as state of the art non-precious transition metal catalysts for the hydrogen evolution reaction (HER). Nevertheless, despite numerous studies dedicated to their electrocatalytic activities, the exact nature of the active sites and their interaction with interfacial water remain largely elusive. In this work, amorphous and crystalline MoS2 catalysts were prepared by electrodeposition and chemical exfoliation, respectively, and compared with other Mo-based compounds. Herein, we show that all of these compounds exhibit two reduction mechanisms in low proton concentration: proton reduction occurs at low overpotential followed by water reduction at higher overpotential. We show that both the chemical composition and the structure of the catalyst influence the activity of the proton reduction but that none of those materials efficiently catalyze water reduction. Finally, we demonstrate by using different cations (Li+, Na+, and K+) or using deuterated electrolytes that the active sites for the proton reduction mechanism are probably different for amorphous and exfoliated crystalline MoS2.

Decoration of the surface of carbon nanoparticles with titania leads to a highly stable desalination capacity during capacitive deionization (CDI) operation in oxygenated saline solution.

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