阅读说明：本技术 一种孔径可控的蜂窝状三维多孔MXene及其通用合成方法 (Honeycomb three-dimensional porous MXene with controllable pore diameter and general synthesis method thereof ) 是由 王治宇 修陆洋 邱介山 于 2019-10-16 设计创作，主要内容包括：本发明公开了一种孔径可控的蜂窝状三维多孔MXene及其通用合成方法,属于纳米材料领域。本发明以二维的过渡金属碳化物MXene和相应的高分子模板为前驱体,通过喷雾热解技术制备了内部孔径大小可控的蜂窝状三维多孔过渡金属碳化物。本发明制得的蜂窝状三维多孔过渡金属碳化物是由二维MXene三维紧密交联而成的分级多孔三维结构,孔径大小在260-800nm,热解时间极短,有着优异的导电性和远超二维MXene的比表面积和孔体积；极大增大了其孔隙率与离子透过性,使MXene表界面得到高效利用,提升了其应用与加工性能,在催化、能源、光电、空间技术、军工等领域具有广泛的应用前景。(The invention discloses a honeycomb three-dimensional porous MXene with controllable pore diameter and a general synthesis method thereof, belonging to the field of nano materials. The invention takes two-dimensional transition metal carbide MXene and a corresponding polymer template as precursors to prepare the honeycomb three-dimensional porous transition metal carbide with controllable internal pore size by a spray pyrolysis technology. The prepared honeycomb three-dimensional porous transition metal carbide is a hierarchical porous three-dimensional structure formed by three-dimensional close crosslinking of two-dimensional MXene, the pore size is 260-800nm, the pyrolysis time is extremely short, and the honeycomb three-dimensional porous transition metal carbide has excellent conductivity and far-exceeding specific surface area and pore volume of the two-dimensional MXene; the porosity and ion permeability of the composite membrane are greatly increased, the MXene surface interface is efficiently utilized, the application and processing performance of the composite membrane are improved, and the composite membrane has wide application prospects in the fields of catalysis, energy, photoelectricity, space technology, military industry and the like.)

1. The general synthesis method of the cellular three-dimensional porous MXene with the controllable pore diameter is characterized by comprising the following steps:

(1) the concentration is 0.5-20mg mL^-1Ultrasonically dispersing the MXene solution and the polystyrene nanospheres to obtain a precursor solution; the diameter of the polystyrene nanosphere is 260-800 nm; the mass ratio of MXene to polystyrene nanospheres is 0.01-100;

(2) atomizing the precursor solution obtained in the step (1) into aerosol micro-droplets by using an ultrasonic atomizer;

(3) and (3) taking inert gas as carrier gas, blowing the aerosol micro-droplets obtained in the step (2) into a high-temperature furnace with the preset temperature of 400-.

2. The general synthesis method according to claim 1, wherein in the step (1), the solvent of MXene solution is at least one of water or alcohol containing 1-11 carbon atoms; the ultrasonic dispersion time is 10-60 min.

3. The universal synthesis method according to claim 1 or 2, wherein in the step (3), the inert gas is at least one of nitrogen, argon and helium, and the carrier gas flow rate is 0.1-5.0L h^-1。

4. Cellular three-dimensional porous MXene nanoparticles obtained by the general synthesis method of any one of claims 1-3, wherein the cellular three-dimensional porous MXene has a size of 0.2-50 μm and a specific surface area of 216.5-284.7m²g^-1Pore volume of 0.682-1.202cm³ g^-1(ii) a The structure is provided with a mutually communicated honeycomb-shaped open pore structure, the internal pore diameter structure is uniform and stable, a honeycomb-shaped three-dimensional porous structure with the pore diameter within the range of 260-800nm and any pore diameter can be obtained by changing the size of the polystyrene nanospheres, and the pore walls are transition metal carbide nanosheets with the thickness of 2-20 nm.

Technical Field

The invention belongs to the field of nano materials, and relates to a honeycomb three-dimensional porous MXene with controllable pore diameter and a general synthesis method thereof.

Background

Nanomaterials have received much attention because of their size effects, their physicochemical properties far superior to those of macroscopic bulk materials. The performance of the functional nano material depends on the appearance, size and crystalline phase structure of the functional nano material to a great extent, the microstructure of the functional nano material is finely regulated, and the realization of structural design and controllable construction become the hot field of scientific research of nano materials in recent years.

MXene is a novel transition metal carbide or nitride two-dimensional crystal obtained by acid etching of a layered ceramic material MAX phase. Having the chemical formula M_n+1X_n(n is 1, 2, 3, M is a transition metal element, and X is carbon or nitrogen). Wherein Ti₃C₂As one of MXene, the graphene material has a two-dimensional structure similar to graphene and excellent electrical, mechanical and magnetic properties. In recent years, the method is widely applied to the fields of energy storage, electromagnetic shielding, water treatment, gas/biological sensing, photoelectrochemical catalysis and the like.

The MXene two-dimensional nanostructure endows the MXene with unique performance, but the MXene sheet layer has small specific surface area and lacks of a pore structure, so that irreversible stacking and agglomeration are easy to occur in the processing treatment process, the specific surface area, the porosity and the ion permeability are greatly reduced, the efficient utilization of the surface interface is limited, the image response is severe, and the application and the processing performance of the MXene in various fields are limited.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a universal synthesis method for controllably constructing the cellular three-dimensional hierarchical porous MXene, the prepared product is formed by three-dimensionally communicating and assembling two-dimensional MXene sheets, the cellular hierarchical porous structure is provided, and the size of the internal pore diameter can be artificially regulated and controlled, so that the requirements on different pore diameters in the production process are met, the problems of small specific surface area, lack of pore structure and the like of the MXene are fundamentally solved, the stacking and agglomeration of the MXene are inhibited, the MXene surface interface can be fully utilized, and the fundamental problem that the MXene performance is brought into play and is widely applied is solved. The synthesis method is environment-friendly, low in energy consumption, easy to control and universal, and can be used for large-scale production.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a cellular three-dimensional porous MXene with controllable pore diameter, the three-dimensional porous MXene has a cellular hierarchical porous structure, the size is 0.2-50 μm, and the specific surface area is 216.5-284.7m² g^-1The pore volume is 0.682-1.202cm³ g^-1(ii) a The porous structure has a mutually communicated honeycomb open pore structure, the internal pore diameter structure is uniform and stable, a honeycomb three-dimensional porous structure with any pore diameter in the range of 260-800nm can be obtained by changing the size of the polystyrene nano-sphere template, and the pore wall is a transition metal carbide nano-sheet with the thickness of 2-20 nm.

A general synthesis method of honeycomb three-dimensional porous MXene with controllable pore diameter comprises the following steps:

(1) the concentration is 0.5-20mg mL^-1And ultrasonically dispersing the MXene solution and the spherical template polystyrene nanosphere for 10-60min to obtain a precursor solution.

The solvent of the MXene solution is at least one of water or alcohol containing 1-11 carbon atoms; the diameter of the polystyrene nanosphere is 260-800nm, and the mass ratio of MXene to the polystyrene nanosphere is 0.01-100.

(2) And (3) atomizing the precursor solution obtained in the step (1) into aerosol micro-droplets with the size of about several microns by using an ultrasonic atomizer.

(3) And (3) taking inert gas as carrier gas, blowing the aerosol micro-droplets obtained in the step (2) into a high-temperature furnace with the preset temperature of 400-.

The inert gas is at least one of nitrogen, argon and helium, and the flow rate of the carrier gas is 0.1-5.0L h^-1。

The invention has the beneficial effects that: compared with the prior art, the invention solves the problems of low specific surface area of the two-dimensional MXene and difficult design, construction, preparation, processing and application of the aperture structure, and specifically comprises the following steps:

(1) in the structure, MXenes are interwoven and mutually supported in a three-dimensional network mode, and uniform and rich porous structures exist among the three-dimensional structures, so that the lamination and agglomeration caused by Van der Waals interaction among the MXenes can be effectively inhibited; meanwhile, the internal pore structure can be finely regulated and controlled, and the uniform distribution of the pore structure between 260 and 800nm can be realized.

(2) The prepared three-dimensional MXene has a specific surface area and an internal pore volume which are superior to those of two-dimensional MXene, shows good dispersibility in solvents with different polarities, is not easy to agglomerate under a solid condition, and has excellent processing characteristics and structural stability.

(3) The method can realize fine regulation and control of the structure, the size and the like of the three-dimensional MXene, has simple process, can realize continuous production, is green and environment-friendly in process and is easy for large-scale production; has wide application prospect in the fields of energy storage, catalysis, photoelectric materials, biological medicines, electromagnetic shielding, wave-absorbing materials and the like.

Drawings

FIG. 1 is a scanning electron microscope photograph of cellular three-dimensional porous MXene having a pore size of 260nm prepared at 400 ℃ in example 1 of the present invention;

FIG. 2 is a transmission electron microscope photograph of cellular three-dimensional porous MXene having a pore size of 260nm prepared at 400 ℃ in example 1 of the present invention;

FIG. 3 is a transmission electron microscope photograph of cellular three-dimensional porous MXene having a pore size of 430nm prepared at 600 ℃ in example 2 of the present invention;

FIG. 4 is a transmission electron microscope photograph of cellular three-dimensional porous MXene having a pore size of 800nm prepared at 800 ℃ in example 3 of the present invention.

Detailed Description

The technical solution of the present invention is proposed to overcome the defects of the prior art, and the technical solution, the implementation process and the principle thereof will be further explained as follows. However, it should be understood that the above-described technical features of the present invention and those specifically described in the embodiments may be combined with each other to constitute a new or preferred technical solution within the scope of the present invention.

Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.