Method for polymer assisted supercritical stripping of transition metal sulfide

Abstract

The invention provides a method for polymer assisted supercritical stripping of transition metal sulfide. The method comprises the following steps: mixing the transition metal sulfide with polyvinylpyrrolidone according to a mass ratio (1-10):1, and placing the obtained mixture in a shearing assisted supercritical device; introducing CO2 into the shearing assisted supercritical device, and carrying out shearing assisted supercritical stripping at a temperature of 32-200 DEG C under a reaction pressure of 8-20 MPa for 10 min to 48 h; and reducing the pressure in the pressure in the shearing assisted supercritical device to half of the reaction pressure or less within 0.1 s after the supercritical stripping, releasing the pressure in the shearing assisted supercritical device to normal pressure, and collecting the above prepared few-layer transition metal sulfide.

Description

technical field [0001] The invention belongs to the technical field of nanomaterial preparation and relates to a method for polymer-assisted supercritical stripping of transition metal sulfides. Background technique [0002] Two-dimensional nanomaterials are a focus research topic in the field of nanomaterials research. In the study of all 2D materials, transition metal sulfides have attracted extensive attention because of the electronic characteristics of superior charge carrier mobility and tunable charge carrier behavior, such as the semiconducting properties and special layered structure of molybdenum disulfide , so that it exhibits many excellent physical and chemical properties, such as large specific surface area, high reactivity, strong adsorption capacity, good catalytic performance, etc., so it is used in lubrication, catalysis, sensing, nano-optoelectronic devices, high-performance composite materials, and Electrochemical hydrogen storage and lithium storage hav...

AI Technical Summary

Problems solved by technology

Chemical vapor deposition method is expected to realize the controllable synthesis of large-area two-dimensional materials, but this method is difficult to scale production, which limits its application

The liquid phase ultrasonic method uses ultrasonic action to insert organic solvents (surface energy is similar to that of layered materials) or surfactant molecules into the interlayer to overcome the cohesive energy density between adjacent layers and achieve peeling, but the preparation During the process, the high-energy ultrasonic effect will cause the size of graphene nanosheets to become smaller, and defects will be introduced on the surface and ends, which limits the application of two-dimensional materials in molecular electronic devices, etc.

The shear-assisted liquid phase exfoliation method uses shear to overcome the van der Waals force between layers to obtain a single-layer or few-layer structure. The main method is mechanical stirring. Large-scale mechanical stirring equipment not only consumes a lot of energy, but also it is difficult to achieve high speed of large-scale mixers. At the same time, there is a dead angle in the reactor.

[0004] It can be seen that the common disadvantages of the current methods for preparing transition metal sulfide two-dimensional nanomaterials are high production costs, great environmental pollution, or long production cycles, and difficulty in large-scale preparation.

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