Liquid Phase Exfoliation of Two-Dimensional Materials by Directly Probing and Matching Surface Tension Components

Abstract

Exfoliation of two-dimensional (2D) materials into mono- or few layers is of significance for both fundamental studies and potential applications. In this report, for the first time surface tension components were directly probed and matched to predict solvents with effective liquid phase exfoliation (LPE) capability for 2D materials such as graphene, h-BN, WS2, MoS2, MoSe2, Bi2Se3, TaS2, and SnS2. Exfoliation efficiency is enhanced when the ratios of the surface tension components of the applied solvent is close to that of the 2D material in question. We enlarged the library of low-toxic and common solvents for LPE. Our study provides distinctive insight into LPE and has pioneered a rational strategy for LPE of 2D materials with high yield.

Two-Dimensional Colloidal Nanocrystals

“…This strategy has been successfully applied to a broad range of materials (graphene, BN, MoS2, WS2, MoSe2, MoTe2, Bi2Se3, TaS2, SnS2, GaS…). 27,215,217,218 One can distinguish two main ways to provide the necessary energy to exfoliate the powders. The first demonstrated one has been to sonicate powders in a suitable solvent such as N-methyl-pyrrolidone (NMP) 216,219 .…”

CoNi2S4‐Graphene‐2D‐MoSe2 as an Advanced Electrode Material for Supercapacitors

“…Consequently, the foams dried at 120 °C for 12 h in a vacuum oven and the dried nickel foams were pressed to be a thin foil at a pressure of 10 MPa for 1 min. Cyclic voltammetry curves were obtained at various scan rates (5,10,20,50, and 100 mV s −1 ) in a potential window of 0-0.4 V. GCD curves were recorded at various current densities (1, 2, 5, 10, and 20 A g −1 ) in a potential window of 0-0.4 V. While in full cell test, the symmetric supercapacitor cell using filter paper as the separator was assembled to measure the device performances. The loading mass of the active materials on Ni foam current collector was controlled to be around 5 mg, and each working electrode had a geometric surface area of 1 cm 2 .…”

“…First, a large amount of high quality graphene and MoSe 2 nanosheets were synthesized based on our previous liquid-exfoliation method. [20] Then, composites of CoNi 2 S 4 -graphene (CoNi 2 S 4 -G), CoNi 2 S 4 -2D MoSe 2 (CoNi 2 S 4 -MoSe 2 ), and CoNi 2 S 4 -graphene-2D MoSe 2 (CoNi 2 S 4 -G-MoSe 2 ) were prepared with an in situ hydrothermal 3D CoNi 2 S 4 -graphene-2D-MoSe 2 (CoNi 2 S 4 -G-MoSe 2 ) nanocomposite is designed and prepared using a facile ultrasonication and hydrothermal method for supercapacitor (SC) applications. Because of the novel nanocomposite structures and resultant maximized synergistic effect among ultrathin MoSe 2 nanosheets, highly conductive graphene and CoNi 2 S 4 nanoparticles, the electrode exhibits rapid electron and ion transport rate and large electroactive surface area, resulting in its amazing electrochemical properties.…”

Liquid Exfoliated Co(OH)2 Nanosheets as Low‐Cost, Yet High‐Performance, Catalysts for the Oxygen Evolution Reaction

“…Relatively high concentrations (~1 mg ml -1 ) can be achieved with nanosheet dimensions of ~100s of nm across by ~nm thick. [26] This method is versatile, [33] having produced a range of 2D materials including graphene, [34] BN, [35] MoS2, [36] SnO, [37] black phosphorous, [38] franckeite, [39] layered silicates, [40] and particularly relevant, nanosheets of Ni(OH)2. [27] Here, we demonstrate that Co(OH)2 nanosheets can be produced by this method.…”