A green route to fabricate MoS₂ nanosheets in water–ethanol–CO₂

Abstract

We show that bulk MoS2 can be efficiently exfoliated into ultrathin nanosheets in supercritical CO2 with ethanol as cosolvent. Moreover, such tailored MoS2 nanostructures, when they are directly used as labels for bioimaging, show excellent imaging effects with strong fluorescence and nontoxicity.

MoS2‐Pt3Au1 Nanocomposites with Enhanced Peroxidase‐Like Activities for Selective Colorimetric Detection of Phenol

“…Notably, among the known strategies for fabrication of MoS 2 NSs, [37][38][39][40][41] the procedure presented here is simple, efficient and economic. It is especially noted that Li-intercalation process, a commonly-used chemical exfoliation method, produces intermediate Li x MoS 2 that is extremely sensitive to air and flammable.…”

Supercritical Fluid‐Facilitated Exfoliation and Processing of 2D Materials

“…[48,76,[78][79][80] Polyvinylpyrrolidone (PVP) outperformed Pluronics F127 and P123, Tween 20, hexadecyltrimethylammonium bromide (CTAB), and sodium dodecylbenzenesulfonate (SDBS) for exfoliation in scCO 2 mixed solvent solutions. [48,76,[78][79][80] Polyvinylpyrrolidone (PVP) outperformed Pluronics F127 and P123, Tween 20, hexadecyltrimethylammonium bromide (CTAB), and sodium dodecylbenzenesulfonate (SDBS) for exfoliation in scCO 2 mixed solvent solutions.…”

“…[143] This synthesis was done by sonicating powdered MoS 2 in DMF, placing this reaction mixture in an autoclave at 400 °C for 30 min, and then quenching at 5 °C. [79] Their two-phase process utilized MoS 2 that was initially dispersed in aqueous ethanol, infused with scCO 2 at 40 °C, and stirred to form Pickering emulsions of scCO 2 and ethanol in an aqueous ethanol continuous phase, with scCO 2 and ethanol solution droplets. The scrolling of nanosheets to form scrolls (and tubes) was explained as a process driven to minimize surface free energy.…”

“…The supernatant was collected and centrifuged to obtain the MoS 2 nanosheets. [79] They did report luminescence properties of multicomponent emission spectra that shift red as excitation wavelengths shift from 300 to 550 nm. This minimization is a pervasive force in nature where Gibbs surface free energy is decreased by minimization of surface area to volume ratios and is a consequence of MoS 2 units being constrained to a sheet structure after exfoliation.…”

CO2‐Assisted Conversion of Crystal Two‐Dimensional Molybdenum Oxide to Amorphism with Plasmon Resonances

“…We also present that bulk MoS 2 can be efficientlye xfoliated into ultrathin nanosheets in supercritical CO 2 with ethanol as co-solvent. [25] The formation of Pickering emulsion in the exfoli-ation processp lay av ital role in obtaining MoS 2 nanosheets withoutu sing surfactants, which is shown in Figure 6. Owing to the compatibilityo fS C-CO 2 with ethanol, two new solution phases can be built, one phaser ich of CO 2 and ethanol, and the second phase rich of MoS 2 and water.T he formation of MoS 2 /waterP ickering emulsion droplets takes place under the high-speed stirring.…”