Rapid preparation method and application of few layer MXenes

Abstract

The invention discloses a rapid preparation method and application of few layer MXenes. According to the preparation method of the few layer MXenes material, a few layer MXenes solution with good dispersibility is obtained by stripping a multi-layer MXenes liquid phase; the electrostatic balance of the few layer MXenes solution with is destroyed by introducing an electrolyte solution, and the obtained sol, precipitate or filter cake is the few layer MXenes material by means of cation-assisted electrostatic precipitation process (such as NH4 +) through standing or low-speed centrifugation or pumping filtration; and then macro-scale preparation of the few layer MXenes powder can be realized through freeze drying and subsequent annealing treatment. The preparation method has advantages of simple process and thin layers, large sheet diameter, good dispersibility, no agglomeration and agglomeration phenomenon and good electrochemical performance of the prepared few layer MXenes and is suitable for large-scale development and application of lithium ion batteries or sodium ion batteries.

Description

technical field [0001] The invention relates to the technical field of nanomaterials, in particular to a rapid preparation method and application of few-layer MXenes. Background technique [0002] MXenes materials are usually prepared by corroding "A" in MAX phase materials. Metal bonds, ionic bonds and covalent bonds coexist in MAX phase crystals, where M is a transition group metal element, and A is mainly the third main group and the fourth group. Main group elements, X is carbon and or nitrogen, M and X are mainly connected in the form of covalent bonds and ionic bonds, and the bonding strength between them is very high; between M and A elements and between A and A elements Most of them are connected by metal bonds, so the strength of chemical bonds is relatively weak. Therefore, as long as an appropriate method is selected to selectively etch the A-layer atoms in the MAX phase, the MXenes material with two-dimensional morphology can be obtained. The MAX is directly etc...

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Problems solved by technology

[0003] The Chinese patent whose authorized notification number is CN106495210B discloses a preparation method of MXenes colloid, by adding H 2 SO 4 solution with NH 4 HF 2 Mixing, using the hydrofluoric acid generated during the mixing process to etch the MAX raw material, the ammonium sulfate produced has endothermic properties, which reduces the intensity of the reaction and avoids the danger of using HF acid directly, but the prepared MXenes The number of material layers is relatively thick, and the combined layer spacing is about 1nm. It is estimated that the number of layers is about 5000 layers, which cannot give full play to the advantages of MXenes two-dimensional materials.

The Chinese patent with application number 201810359588.8 discloses a preparation method of three-dimensional MXenes. By dispersing MXenes in a solvent and ultrasonically dispersing, the multi-layer MXenes are peeled off into a few layers, and then the MXenes powder is prepared by freeze-drying. Because the solution It contains a large amount of water, which makes the freeze-drying process relatively slow (conventional freeze-drying machine, it takes about 2 days to freeze-dry 5ml of water in a centrifuge tube), and the whole preparation process is time-consumi

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