679results about "Titanium carbide" patented technology

The present disclosure describes electrochromic devices comprising transparent conductive layer acting as an electrode, an active electrochromic film, an ion conductor, and an ion storage film at least one of which comprises at least one MXene material.

The invention provides an alkaline ion battery negative electrode material as well as a preparation method and application thereof, and particularly relates to an MXene / MoS2 / TiO2 composite material which is prepared by the following steps: etching an MAX phase by using mixed acid containing HF to obtain MXene; performing freeze drying to obtain powder containing MXene, a Mo source and an S source; and calcining to obtain the composite material. According to the negative electrode material disclosed by the invention, MoS2 is supported by utilizing high conductivity of MXene and structural collapse of the MoS2 is relieved, and TiO2 enhances cycle stability, is designed for a negative electrode of an alkaline ion battery and shows good cycle performance. MXene is obtained by etching an MAX phase with mixed acid, the composite material is prepared by combining freeze drying and calcination, NH prevents MXene from stacking and expands interlayer spacing, MoS2 is formed after calcination, and a small amount of TiO2 is generated in situ. And the single-layer MXene is used as a binder to replace a traditional material, so that the electrochemical performance of the composite electrode is improved.

The invention provides an Mxene-iron molybdenum bimetallic sulfide and carbon composite material as well as a preparation method and application thereof, belongs to the technical field of sodium ion batteries, and is used for solving the technical problems of poor conductivity and rate capability of a metal sulfide negative electrode material. The preparation method of the Mxene-iron-molybdenum bimetallic sulfide and carbon composite material comprises the following steps: dissolving an iron source, a molybdenum source and a carbon source in a solvent to prepare a mixed solution; then carrying out a hydrothermal reaction to prepare a bimetallic oxide nanosphere; the bimetallic oxide nanospheres are subjected to high-temperature vulcanization treatment, and iron-molybdenum bimetallic sulfide carbon is prepared; the preparation method comprises the following steps: mixing Mxene and iron-molybdenum bimetallic sulfide and carbon through ball milling to prepare the Mxene-iron-molybdenum bimetallic sulfide and carbon composite material. The composite material disclosed by the invention can realize efficient electron transmission and provide more active sites, and is beneficial to the electrochemical reaction of the battery; the mechanical stability of the material can be enhanced, the volume expansion in the charging and discharging process is effectively reduced, the particle diffusion path between positive and negative electrodes is shortened, and the reaction kinetics of the electrode is improved; and the conductivity and the rate capability of the material can be effectively improved, so that the comprehensive performance of the sodium-ion battery is improved.

The invention belongs to the technical field of battery materials, and particularly relates to an MXene material composite nickel-iron-manganese-based positive electrode material and a preparation method and application thereof. The chemical formula of the MXene material composite nickel-iron-manganese-based positive electrode material is NaNiaFebMncTMdO2 (at) MXene, TM is one or more of Mg, Al, Ti, Zn, Zr, Cu, Nb, W and Mo, values of a, b, c and d depend on charge balance, M in MXene is one or more of Ti, Nb, V, Mo, Ta, Cr and Hf, X is C or N, and ene represents a structural unit of graphene. MXene is compounded with the nickel-iron-manganese-based positive electrode material, so that the situation that the nickel-iron-manganese-based positive electrode material is in contact with water and CO2 in air to inhibit the interface side reaction between electrolyte and the nickel-iron-manganese-based material can be reduced, and excellent cycling stability is shown under high voltage.

The invention discloses a method for preparing antioxidant MXene through electrochemical stripping, and belongs to the technical field of two-dimensional nano materials. Comprising the following steps: (1) centrifuging a Ti < 3 > C < 2 > T < x > MXene dispersion liquid to obtain a MXene wet solid, and coating the MXene wet solid on two sides of a copper foil; (2) the copper foil coated with the MXene wet solid serves as a cathode, and the cathode and the anode are placed in an electrolytic tank together; and (3) applying a constant voltage for electrolysis, collecting sediments in an electrolytic tank, centrifuging, washing, carrying out suction filtration, and drying to obtain the e-MXene film. The e-MXene prepared by the invention has excellent oxidation resistance and adjustable infrared emissivity, and can adapt to infrared camouflage application under damp and hot conditions.

The invention discloses a natural polysaccharide assisted MXene porous membrane electrode and a preparation method thereof, and relates to the technical field of electrodes. According to the technical scheme, hydrochloric acid and lithium fluoride are used for carrying out etching and intercalation on an MAX raw material, and MXene dispersion liquid is obtained; mixing the MXene dispersion liquid with a metal ion solution to obtain a metal ion doped MXene solution; mixing the metal ion doped MXene solution with a natural polysaccharide dispersion liquid to obtain a natural polysaccharide modified MXene dispersion liquid; mixing the natural polysaccharide modified MXene dispersion liquid with a template substance, performing vacuum filtration, and performing vacuum drying to obtain a flexible MXene film; and carrying out template substance removal treatment on the flexible MXene film to obtain the natural polysaccharide-assisted MXene porous film electrode. According to the invention, the stacking problem of the MXene material is solved, and the electrochemical performance of the natural polysaccharide-assisted MXene porous membrane electrode is obviously improved.

The present invention proposes a preparation method of chemically modifying the surface of traditional aramid fiber with dopamine and then grafting two-dimensional titanium carbide (MXene) flakes, so that the modified aramid fiber has good electrical conductivity and excellent electromagnetic shielding effectiveness while maintaining flexibility, and the electromagnetic shielding effectiveness in the X-band (8.2GHz~12.4GHz) can be up to 85dB. The preparation method of the present invention comprises: soaking the cleaned aramid fiber in a dopamine hydrochloride solution, adding a MXene dispersion, and adjusting the pH of the system so that dopamine nucleates and self-polymerizes on the surface of the aramid fiber and the MXene flakes. During this polymerization process, the MXene flakes will be fixed on the surface of the aramid fiber by filamentous polydopamine. The method is simple in process, the grafted MXene flakes are evenly distributed and not easy to fall off, no toxic solvents are required, and no toxic gas / liquid is discharged. The waste liquid generated can be directly discharged after adjusting the pH, which is energy-saving and environmentally friendly.

The invention discloses a two-dimensional layered MXene nanosheet and a preparation method thereof, and belongs to the technical field of MXene preparation. The method comprises the following steps: (1) etching an MAX phase powder material by using hydrofluoric acid to obtain an etched MAX phase; (2) centrifuging and drying the etched MAX phase to obtain multi-layer MXene powder; (3) carrying out homogenization treatment on the multiple layers of MXene powder; and (4) carrying out rapid annealing treatment on the powder obtained after homogenization treatment to remove functional groups on the surface of MXene so as to prepare the MXene nanosheet with a regular structure and few defects. The method effectively avoids the oxidation problem of MXene, realizes feasible preparation with uniform thickness, stability, regular shape and fewer defects, and has the advantage of replacing an organic reagent intercalation preparation method to become a mainstream preparation method.

The invention belongs to the technical field of two-dimensional material preparation, and provides a method for preparing an MXene material based on a free radical mechanism, and the method comprises the following steps: S1, carrying out acid pickling on MAX phase powder to obtain an acid pickling precursor; s2, mixing the pickling precursor, an organic halogenation reagent and a buffer reagent, and then performing an etching reaction under an ultraviolet irradiation condition; s3, after the etching reaction is completed, an obtained product is cleaned and dried, and the MXene material is obtained. According to the method, the organic halogenation reagent is irradiated by ultraviolet light, so that the halogen free radicals are excited, and the halogen free radicals are used as an etching agent to realize selective etching of the A layer in the MAX phase material, so that the MXene material is prepared. The method has the characteristics of safety and environmental protection.

The invention provides an intrinsic magnetic MXene material and a preparation method and application thereof, the preparation method comprises the following steps: S1, mixing an aqueous solution of MXene with an alkaline reagent, and carrying out ultrasonic dispersion to obtain a mixed dispersion liquid; freezing the mixed dispersion liquid into a solid by liquid nitrogen; the alkaline reagent is potassium hydroxide or sodium hydroxide; s2, the obtained solid is subjected to freeze drying, and the Archimedes screw type MXene aerogel is obtained; s3, the Archimedes spiral type MXene aerogel is subjected to heat treatment under the protection of inert gas, and the intrinsic magnetic MXene material is obtained. The invention designs and develops a single-component pure MXene electromagnetic wave absorbing material on the premise of not introducing magnetic nanoparticles.

The invention discloses a preparation method and application of a two-dimensional composite material. The preparation method comprises the following steps: adding MXene into formamide, carrying out ultrasonic dispersion to obtain an MXene formamide dispersion liquid, then adding MgAl LDH into the MXene formamide dispersion liquid, carrying out magnetic stirring, washing with absolute ethyl alcohol, and carrying out vacuum drying to obtain a two-dimensional composite material which is marked as MgAl LDH / MXene. The two-dimensional composite material is used for a lithium-sulfur battery diaphragm barrier layer so as to inhibit the shuttle effect of polysulfide. The preparation method is simple and environment-friendly, and the prepared MgAl LDH / MXene two-dimensional composite material is high in specific surface area, has strong affinity to polysulfide, can promote rapid transmission of lithium ions, can provide an instant electron conduction way for adsorbed polysulfide, is applied to a diaphragm barrier layer of a lithium-sulfur battery, and has a good application prospect. The wettability of the electrolyte on the diaphragm and the conversion of polysulfide are enhanced, the problem of volume expansion in the cycle process of the lithium-sulfur battery is relieved, and the redox reaction kinetics is accelerated.

The invention discloses functionalized few-layer MXene, a preparation method and a high-conductivity proton exchange membrane, and the preparation method comprises the following steps: etching treatment, alkalization treatment, ultrasonic treatment, rotary evaporation concentration and optional modification treatment to obtain a functionalized few-layer MXene (less than five layers) concentrated solution; the functional few-layer MXene and the protonated polymer are compounded to prepare the high-conductivity proton exchange membrane f-MXene / PA-PBI, so that the mechanical property and the proton conductivity of the PA-PBI membrane are well improved, and particularly the proton conductivity at low temperature is improved. According to the invention, the high stability of the interlayer intercalation water of the functionalized few-layer MXene at high temperature is utilized, so that the high-temperature and high-conductivity proton exchange membrane fuel cell stack can realize multiple times of high-temperature and low-temperature start-stop switching, and the practical application of the PA-PBI high-temperature proton exchange membrane fuel cell is greatly facilitated.

Ultrafast flash evaporation joule heating synthesis methods and systems, more particularly, ultrafast synthesis methods for recovering metals from ores, fly ash, and bauxite residue (red mud).

The invention provides a titanium carbide preparation process, and relates to the technical field of carbide preparation, the titanium carbide preparation process comprises the following steps: S1, selecting ilmenite with the phosphorus content of less than 100 ppm, crushing, reducing, concentrating, hydrolyzing, washing and filtering to generate a titanium dioxide filter cake; the pore diameter of titanium dioxide is controlled to be 1-5nm, the phosphorus content is less than 50ppm, and the sulfur content is less than 0.1%; s2, pulping the titanium dioxide filter cake obtained in the step S1 to form primary slurry, adding carbon black according to the content of titanium dioxide, and uniformly stirring to form secondary slurry; s3, continuously stirring the secondary slurry, and pumping the secondary slurry into a spray dryer for spray drying to generate titanium dioxide-carbon black particles; and S4, the titanium dioxide-carbon black particles pass through a high-temperature roasting area under the action of airflow and gravity to generate titanium carbide powder. According to the method, the mixing uniformity of the carbon black is larger than or equal to 95%, the yield of the titanium carbide is increased to 99.5% or above, and the quality and the yield of the finished titanium carbide are greatly improved.

The present disclosure provides Max and MXene using low-cost vanadium carbide instead of an expensive vanadium metal, and a method for preparing same.

The invention discloses a double transition metal doped graphene catalyst and application thereof, the double transition metal doped graphene catalyst is of a hexagonal crystal system structure, and the space group is P6 / mmm; the composition form of the active center is Cu2C3N3, Nb2C3N3, Ta2C3N3, Rh2C6, Rh2C3N3 and Rh2N6, the hydrogen evolution free energy of the active center is-0.03 eV,-0.09 eV, 0.10 eV, 0.12 eV,-0.21 eV and 0.06 eV respectively, the metal binding energy of the active center is-4.53 eV,-8.60 eV,-8.03 eV,-6.13 eV,-7.11 eV and-5.62 eV respectively, the metal forming energy of the active center is-0.54 eV,-1.94 eV,-0.06 eV,-0.64 eV,-1.62 eV and-0.13 eV respectively, and the active center has good catalytic activity, structural stability and preparation feasibility and is used for

The invention relates to the field of nano materials and electrochemical technology materials, in particular to a melamino-formaldehyde / MXene composite material, a derived carbon material thereof, a preparation method and application. According to the preparation method disclosed by the invention, MXene is taken as a substrate, and protonated melamine formaldehyde molecules are inserted into MXene layers through an electrostatic self-assembly effect, so that the melamine formaldehyde / MXene composite material is synthesized; and carrying out high-temperature calcination on the basis to prepare the melamine formaldehyde / MXene composite material derived carbon material. According to the invention, active sites for adsorption and catalytic conversion of iodine species are provided while self-stacking of MXene is solved, and the melamine formaldehyde / MXene composite material is used as the positive electrode material of the aqueous zinc-iodine battery, so that the iodine species can be effectively anchored, and the active sites for catalytic conversion of iodine are fully provided; the reversibility and the structural stability of the electrode reaction are enhanced, so that the electrochemical performance of the battery is greatly improved.

The invention discloses a preparation method of an interlayer spacing adjustable MXene material through microwave-assisted chemical etching, and belongs to the technical field of two-dimensional nano material preparation. Key parameters such as etching agent solution concentration, villiaumite ratio and microwave power are adjusted and controlled through a synergistic effect mechanism of a microwave field and chemical etching; the preparation method realizes accurate and controllable interlayer spacing preparation of the MXene material, has the advantages of high reaction speed, high etching efficiency, accurate and adjustable interlayer spacing, wide range and the like, and provides an efficient and reliable preparation method for performance optimization of the MXene material in the fields of energy storage, catalysis, separation membranes, gas sensitivity and the like.

A paste that includes particles of a layered material in an ammonia aqueous solution. The particles include one or plural layers, the layers having a layer body represented by MmXn, wherein M is at least one metal of Group 3, 4, 5, 6, or 7, X is a carbon atom, a nitrogen atom, or a combination thereof, n is not less than 1 and not more than 4, and m is more than n but not more than 5, and a modifier or terminal T exists on a surface of the layer body, wherein T is at least one selected from the group consisting of a hydroxyl group, a fluorine atom, a chlorine atom, an oxygen atom, and a hydrogen atom, wherein the paste has a viscosity of 1 Pa·s or more at a shear velocity of 1 / s when the paste has a solid content concentration of 1.0% by mass.

The invention discloses a method for in-situ growth of a Ti3C2Tx-titanium dioxide heterogeneous interface material and application, and belongs to the technical field of two-dimensional composite materials and gas sensors, a hydrochloric acid solution of a fluorine-containing compound is used as an etching solvent, a hydrothermal method is adopted to etch Ti3AlC2 to prepare the Ti3C2Tx material (Tx =-F,-OH and-O), and the Ti3C2Tx-titanium dioxide heterogeneous interface material is prepared through a hydrothermal method. The Ti3C2Tx material is subjected to oxygen microwave plasma treatment under low power, meanwhile, the volume fraction of oxygen is controlled to range from 10% to 30%, the Ti3C2Tx material can be partially oxidized into two-dimensional flaky TiO2 oxide, the two-dimensional flaky TiO2 oxide tightly wraps the surface of Ti3C2Tx, and the Ti3C2Tx-TiO2 heterogeneous interface material is formed. The gas sensor prepared from the Ti3C2Tx-TiO2 heterogeneous interface material has very good responsiveness and selectivity to hydrogen gas.

The present invention pertains to a MAX precursor having a reduced oxygen content, and a method for producing MXene. A method for producing a MAX precursor according to the present invention comprises the steps of: applying a physical force to a mixture of a lower metal oxide and at least one among a nitrogen source and a carbon source; heat-treating the mixture to prepare a metal nitride or metal carbide; and synthesizing the metal nitride or metal carbide with aluminum or silicon to produce the MAX precursor.

The invention relates to a preparation method and application of an oxidation-resistant MXene material with a defect ordered hexagonal hole structure, and the preparation method comprises the following steps: mixing MAX phase Ti3AlC2 with hexagonal holes, CuCl2 and NaCl, loading into an alumina corundum square, covering with a NaCl salt bed boat, putting into a muffle furnace, and carrying out constant-temperature sintering at 820 DEG C in an air atmosphere for 3 hours; the method has the advantages that the process is simple and reasonable, a barrier for resisting attacks of oxygen molecules and water molecules is effectively constructed under the combined action of trace metal oxides on the surface of the MXene material, and the oxidation resistance of the MXene material is remarkably improved.

The invention relates to the technical field of temperature sensors, in particular to a preparation method and application of a thermosensitive composite temperature sensor, and the preparation method comprises the following steps: 1, synthesizing MXene; step 2, preparing a thermosensitive composite material; step 3, preparing the thermosensitive temperature sensing yarn or fabric; 4, packaging the modified cashmere yarn or cashmere fabric; the application range of the temperature sensor is widened; not only is the production cost remarkably reduced, but also the uniformity and stability of the composite material on the substrate are ensured, and feasibility is provided for large-scale industrial production; the environment adaptability and the long-term service life of the sensor are greatly improved, the design breaks through the limitation that a traditional flexible temperature sensor is prone to being interfered by the environment and is fast in performance attenuation, and technical guarantee is provided for high-reliability intelligent textiles.

The invention provides a preparation method of an organ-shaped MXene and one-dimensional WO3 nanorod nano self-reduction growth Au nanoparticle NO2 gas-sensitive composite material. The preparation method comprises the following specific steps: (1) preparing a high-molecular flexible substrate; (2) preparation of organ-shaped MXene; (3) preparing an MXene / WO3 composite material; and (4) preparation of an MXene / WO3 / Au composite material: the adding mass of accordion-shaped MXene is 5-160 mg, the adding amount of tetrachloroauric acid (HAuCl4. 3H2O) is 30 [mu] L, the product obtained by reaction is the MXene / WO3 / Au composite material, and the flexible substrate on which the composite gas sensitive material is deposited is the prepared NO2 sensor. The organ-shaped MXene and one-dimensional WO3 nanorod self-reduction growth Au nanoparticle NO2 gas-sensitive composite material prepared by the invention has a uniformly dispersed composite structure, the introduction of the organ-shaped MXene effectively improves the conductivity of WO3, and meanwhile, rich functional groups on the surface of the composite material contribute to improving the gas-sensitive property of WO3. Different electrodes can be deposited on the flexible substrate, the cost is low, the steps are simple and controllable, the flexibility is good, the sensitivity is high, and NO2 detection can be realized at room temperature.

The invention relates to the field of materials, and provides a layered Ti3C2Tx / MXene loaded FeCo nanoparticle composite material, a preparation method and application, FeCo nanoparticles prepared by a hydrothermal method and Ti3C2Tx / MXene prepared by an in-situ etching method are combined by adopting an electrostatic self-assembly method, so that the composite material with a layered structure is obtained, and the FeCo nanoparticles with soft magnetic properties are loaded between layers and on the surface of the Ti3C2Tx / MXene material. The FeCo nanoparticles can adjust the dielectric property of the composite material, so that the composite material can be widely applied to the field of wave absorption. The method has the beneficial effects of simple equipment, low production cost, high production efficiency, greenness and no pollution. The composite material is a high-reflection and low-absorption material in the frequency band of 170-220GHz, and the absorption rate is 10-30%. In the range of 0.2-3 THz, the product prepared by the method also has a wave-absorbing effect, and the absorption coefficient is 100-150 cm <-1 >.

The invention relates to the technical field of silica powder surface modification, in particular to a novel silica powder surface modification method and application of a composite material of the novel silica powder surface modification method. Silica powder surface modification comprises the steps that silica powder is subjected to surface chemical modification through a titanate coupling agent, active functional groups are introduced, and the interface bonding force between the silica powder and MXene is enhanced; high-quality preparation of MXene: etching an MAX phase by adopting hydrofluoric acid (HF) or lithium fluoride / hydrochloric acid (LiF / HCl), and obtaining few layers of MXene nanosheets through ultrasonic stripping to ensure high conductivity and large specific surface area; the modified silica powder and MXene dispersion liquid are uniformly mixed, MXene stacking is inhibited, the specific surface area is increased, and the ion transmission efficiency is improved; mXene nanosheets grow on the surface of the silica powder in situ to form a core-shell structure, so that the interface bonding strength and the mechanical property are enhanced; the composite material is applied to the fields of electromagnetic shielding, energy storage, flexible electronics and the like.

The invention discloses an MXene quantum dot tip heterojunction material with high photothermal conversion efficiency. The MXene quantum dot tip heterojunction material comprises a substrate and a Co3O4 nanoneedle array structure grown on the substrate in situ, ti3C2MXene quantum dots are loaded on the surface of the Co3O4 nanoneedle, and the Ti3C2MXene quantum dots are fixed on the surface of the Co3O4 nanoneedle through the interaction force of heterogeneous charges. The invention also discloses a preparation method of the MXene quantum dot tip heterojunction material. The preparation method comprises the following steps: (1) preparing a Co3O4 nanoneedle structure arranged in an array on a substrate by using a hydrothermal method; and (2) under the irradiation of an ultraviolet lamp, putting the product in the step (1) into an MXene quantum dot solution, and soaking for 6-8 hours.

The invention discloses a modification method of functionalized MXene, and a preparation method and application of a diaphragm, and belongs to the technical field of flow batteries, the modification method comprises the following steps: preparing MXene from MAX ceramic powder through a mixed acid etching method; preparing an MXene nanosheet; sequentially adding the dried MXene nanosheet, amino-containing aromatic small organic molecules and a diazonium salt initiator according to a molar ratio of (1-1.5): (7-9.5): (7-9.5), wherein the diazonium salt initiator is tert-butyl nitrite or isoamyl nitrite; carrying out vacuum pumping, and reacting for 8-12 hours at the temperature of 60-80 DEG C, so as to obtain the organic micromolecule covalently grafted functionalized MXene. On the basis of mild diazonium salt reaction, different functional groups can be connected according to application requirements to obtain organic micromolecule covalently grafted functionalized MXene, so that the electrochemical performance of the flow battery diaphragm material is improved.

The invention belongs to the technical field of preparation of gas sensor materials, and particularly relates to a method for preparing a room-temperature MXene-based ethanol sensor material by using supercritical carbon dioxide. The method comprises the following steps: firstly, carrying out hydrothermal reaction on titanium dioxide powder to obtain titanium nanotubes (TNTs); then carrying out high-temperature calcination on the TNTs; and then the calcined titanium nanotube and MXene are stirred to react under the supercritical COC condition, and finally MXene composite material powder is obtained. The material shows excellent response performance to ethanol gas at room temperature, including short response and recovery time (lt: 5 seconds) and resistance change rate as high as 42%. According to the invention, the electrical conductivity of MXene and the gas sensitivity of TiOnanotubes are fully exerted, the supercritical treatment means is combined, the preparation process is simple, convenient, green and environment-friendly, and the method has a good industrial application prospect and is especially suitable for the field of VOCs gas sensors which are low in power consumption and operate at room temperature.