Stability and Nature of Chemically Exfoliated MoS₂ in Aqueous Suspensions

Abstract

We reveal that chemically exfoliated MoS nanosheets undergo lateral fracture and aggregation upon prolonged storage of the dispersion in ambient air, which was found to be associated with the reoxidation of the nanosheets. Such nanosheet degradation could be effectively prevented by storing the sample in an inert atmosphere to suppress the reoxidation process.

Monolayer Attachment of Metallic MoS2 on Restacked Titania Nanosheets for Efficient Photocatalytic Hydrogen Generation

“…1T-phase MoS 2 nanosheets were prepared through chemical exfoliation according to the literature . First, the starting crystals were pre-expanded by refluxing in N 2 H 4 at 130 °C for 24 h. , The resulting powders were then lithiated by a 2.5-fold molar excess of the n -hexane solution of n -butyllithium in an Ar-filled drybox. The lithiated product was recovered by filtration and washed with hexane.…”

Liquid Phase Exfoliation of MoS2 Assisted by Formamide Solvothermal Treatment and Enhanced Electrocatalytic Activity Based on (H3Mo12O40P/MoS2)n Multilayer Structure

“…In contrast, the proportion of the reduced state of Mo 4+ was enhanced after the treatment temperature was increased. During the solvothermal treatment in the formamide, some intermediates might be produced (such as the reduction of Mo 4+ ), which can accept extra electrons . That is to say, the shifts to lower binding energy are attributed to the enhanced electron density around the Mo and S atoms.…”

“…During the solvothermal treatment in the formamide, some intermediates might be produced (such as the reduction of Mo 4+ ), which can accept extra electrons. 23 That is to say, the shifts to lower binding energy are attributed to the enhanced electron density around the Mo and S atoms. As a result, the repulsion between the adjacent layers is enhanced, which is beneficial to the exfoliation of bulk MoS 2 .…”

“…Among the top-down methods, mechanical exfoliation produces high-quality monolayers but with the deficiency of low yield . On the other hand, ion-intercalation is desirable in achieving high exfoliation yield and high purity of nanosheets, but the need for strong intercalating agents, long reaction time, and strict storage conditions stand as the challenges for large scale application. − Liquid phase exfoliation, first utilized by Coleman, is considered to be a very promising method toward the large scale production of monolayer MoS 2 . , However, the low yield of monolayer production restricts further application and development of this method . In order to enhance the exfoliation efficiency, many efforts have been applied, such as temperature control, ionic liquids assist, solvent grinding assist, sequential solvent exchange, and trace water assist .…”

Multilayer Conductive Hybrid Nanosheets as Versatile Hybridization Matrices for Optimizing the Defect Structure, Structural Ordering, and Energy‐Functionality of Nanostructured Materials

“…[ 15 ] Such physical features of multilayer hybrid NSs are advantageous for improving the structural ordering and charge transport properties of hybridized 2D nanospecies via the flattening of layered crystallites on a robust NS substrate. For example, an exfoliated 1T′‐MoS 2 NS, one of the most efficient electrocatalysts for hydrogen evolution reaction (HER), suffers from low structural stability caused by the facile defect formation/lateral fracture and the resulting degradation of electrocatalyst performance, [ 16 ] which might be relieved by the hybridization with robust multilayer NS substrate. Additionally, the incorporation of rigid multilayer NSs is effective in enhancing the porosities of the resulting nanohybrid due to the fact that the tight packing of flexible thin 2D NS crystallites is prevented.…”