Ultrasound-Assisted Alkaline Solution Reflux for As-Exfoliated MoS₂ Nanosheets

Abstract

A facile approach was developed to produce MoS 2 nanosheets by ultrasound-assisted reflux exfoliation, which was highly efficient for large-scale production and sustainable for environment. The interlayer force of bulk MoS 2 was first exhausted in employing LiOH/NaOH solution by reflux and thereafter quickly exfoliated by ultrasound. The lateral size of the as-prepared MoS 2 nanosheets with about 2–9 layers became smaller. Definitely, the average friction coefficient and wear scar diameter of 0.08 wt % MoS 2 -based oil decreased by about 21.87 and 38.09% relative to the base oil, which displayed better antifriction and antiwear performances.

High Frequency Sonoprocessing: A New Field of Cavitation‐Free Acoustic Materials Synthesis, Processing, and Manipulation

“…1 kHz-1 MHz, although higher-frequency operation (up to GHz) can be achieved with ultrathin plate resonators Ultrasonic bath (typically 1-50 kHz) Bulk crystals: Crystallization, [55] including that of metal-organic frameworks [ 56,57] Nanomaterials: Liquid phase exfoliation of graphene [58] and transition metal dichalcogenides [ 59,60] ; synthesis of carbon nanotubes, [61] nanofibers, [62] and liquid metal droplets [63] Polymeric and biological materials: Polymer synthesis [ 64,65] ; transdermal drug delivery [66] ; intracellular delivery [67][68][69] Ultrasonic nebulizers (typically 1 kHz-2 MHz)…”

Molybdenum disulfide, exfoliation methods and applications to photocatalysis: a review

“…The technique proved to be more effective than other methods, and the thickness and lateral size of the prepared MoS 2 nanoflakes were reduced, showing nanoflakes with approximately 2 to 9 layers. 71 Organic solvents play a crucial role in the exfoliation process. The selection of solvents depends on several parameters such as surface tension and Hildebrand and Hansen solubility parameters.…”

Polarized luminescence of MoS-=SUB=-2-=/SUB=- nanodots

“…MoS 2 nanoparticles were produced by chemical exfoliation and dispersion of massive MoS 2 ( " top-down" method) in alkali solutions under ultrasound exposure [23]. Molybdenum disulfide powder (MoS 2 , particles size < 2 µm, 98%, Aldrich) with a mass of 1.5 g was put into 10M water solution of LiOH and NaOH (mole ratio is 1 : 2).…”