466results about "Titanium carbide" patented technology

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 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 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 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 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 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.

The application discloses a kind of high-conductivity MXene-based electromagnetic shielding composite films and preparation method thereof, belong to new material technical field.The preparation method includes the following steps: using in-situ HF etching method to prepare MXene dispersion liquid;With deionized water as solvent, silver nitrate solution is prepared by dissolving silver nitrate;The silver nitrate aqueous solution is added to MXene dispersion liquid, and Ag@MXene film is obtained by vacuum filtration method.The method uses silver ion in silver nitrate as oxidant to make it and titanium element in MXene occur redox reaction to generate silver particles, so as to prop up MXene sheet layer and reduce the resistance caused by adhesion between sheet layers and increase the conductive path in MXene, so as to increase the conductivity of MXene;The composite film not only has excellent conductivity, electromagnetic shielding performance and is easy to form processing;The conductivity of the composite film can reach 3120S / cm, and the electromagnetic shielding performance can reach 68.5dB.

The present invention discloses a negative electrode porous carbon material and a preparation method thereof, belonging to the technical field of negative electrode materials for sodium ion batteries. The carboxyl groups of acrylic acid react with the carboxyl groups of 2-hydroxyaniline, and the remaining hydroxyl groups combine with silanol groups generated by hydrolysis of 3-mercaptopropyltrimethoxysilane. Sulfonic acid-modified acrylic acid / aniline is obtained under the action of hydrogen peroxide. After calcination, sulfur- and nitrogen-doped conductive hollow carbon spheres are formed. Sulfur doping can participate in the formation of the SEI film, generate a stable interface layer, reduce electrolyte decomposition and irreversible consumption of active lithium, and improve the initial coulombic efficiency. Nitrogen doping can construct an electron high-speed channel and improve conductivity. The conductive hollow carbon spheres are coated with MXene nanosheets and deposited on the surface of foamed carbon. Through the three-level synergy of layered, hollow, and foamed forms, a rigid-flexible effect can be achieved while alleviating volume expansion.

The invention discloses a negative electrode porous carbon material and a preparation method thereof, and belongs to the technical field of sodium ion battery negative electrode materials, carboxyl of acrylic acid reacts with carboxyl of 2-hydroxyaniline, residual hydroxyl groups are combined with silicon hydroxyl generated by hydrolysis of 3-mercaptopropyltrimethoxysilane, and the negative electrode porous carbon material is obtained. Sulfonic acid modified acrylic acid / aniline is obtained under the action of hydrogen peroxide, sulfur and nitrogen doped conductive hollow carbon spheres are formed after calcination, sulfur doping can participate in formation of an SEI film, a stable interface layer is generated, electrolyte decomposition and irreversible consumption of active lithium are reduced, the first coulombic efficiency is improved, and nitrogen doping can construct an electron high-speed channel and improve conductivity. The conductive hollow carbon spheres are coated with the MXene nanosheets and deposited on the surface of the foamy carbon, and the effect of combining rigidity and softness can be achieved while volume expansion is relieved through layered, hollow and foamy three-stage synergism.

The present invention provides a halogen-free MXene represented by the following formula (1), that has no halogen in its surface functional group by performing an etching process to generate MXene from a MAX Phase material, and after the etching process, performing an impurity removal treatment process of etching and removing impurities using a halogen-free etchant and a halogen-free post-treatment agent, respectively.Mn+1XnTx  [Formula 1]wherein, M is a transition metal element selected from the group consisting of Sc, Ti, V, Cr, Mn, Y, Zr, Nb, Mo, Hf, and Ta, X is at least one of carbon and nitrogen, and n is an integer from 1 to 4, and Tx is a functional group selected from the group consisting of oxygen, alkoxide of 1 to 5 carbon atoms, alkyl, carboxylate, hydroxide, hydride, oxide, sub-oxide, nitride, sub-nitride, sulfide, sulfonate, thiol, and epoxide.

A preparation method and application of a defect-ordered hexagonal pore structure antioxidant MXene material, comprising mixing hexagonal pore MAX phase Ti3AlC2 with CuCl2 and NaCl, loading into alumina corundum squares, and covering with a NaCl salt bed boat, placing the mixture in a muffle furnace, and sintering at a constant temperature of 820°C for 3 hours in an air atmosphere; after washing to remove impurities, the mixture is filtered, vacuum dried, and ground to obtain a defect-ordered hexagonal pore structure antioxidant. The advantages are: a simple and reasonable process, and under the joint action of trace amounts of metal oxides on the surface of the MXene material, an effective barrier against attacks by oxygen and water molecules is constructed, significantly improving the antioxidant properties of the MXene material.

The invention provides a method for improving the performance of an MXene-based water evaporation power generation device, and belongs to the technical field of water evaporation power generation devices. The method comprises the following steps: mixing FeCl2. 4H2O, deionized water, ascorbic acid and ethylene glycol, and introducing N2 or Ar to obtain an etching solution; adding carbon nanotubes into the etching liquid, and adjusting the pH value to 4; adding MAX powder into the etching solution, and carrying out etching reaction and standing treatment to obtain supernate; centrifugally washing and drying the supernate to obtain a precipitate; preparing the precipitate into a solution, performing suction filtration on filter paper, and performing drying treatment to obtain an MXene / CNT / filter paper composite film; and connecting conductive parts to the upper and lower ends of the MXene / CNT / filter paper composite film to obtain the water evaporation power generation device. The CNT is synchronously assembled through in-situ hydroxyl radical acidification and etching, so that the CNT and the MXene film form chemical bonding, and the current and voltage of the device are effectively improved.

This invention belongs to the field of microwave absorbing material preparation technology, and discloses a two-step partial oxidation method to improve the microwave absorption performance of MXene materials. By performing hydrothermal pre-oxidation and heat treatment on MXene materials, oxide nanoparticles are grown in situ on their surface, achieving controllable partial oxidation. The MXene matrix retains a two-dimensional layered structure, and a heterogeneous interface is formed between the oxide nanoparticles and the MXene matrix. This adjusts the conductivity, optimizes impedance matching, enhances interface polarization, improves microwave absorption performance, and provides high-temperature stability.

The invention discloses a morphology-controllable Ti3C2T x MXene / Co / C composite material, preparation method and application thereof, the present invention prepares Ti3C2T by hydrothermal carbonization method x MXene / Co / C absorbing material. Different amounts of NH3·H2O are added to the precursor mixed solution to adjust the pH of the solution, change the surface energy of different crystal faces, change the growth mode of the crystal to a certain extent, and calcine to synthesize single-substance Co magnetic nanomaterials of different dimensions. The present invention breaks the limitations of traditional preparation methods. In the prepared absorbing material, the dosage of NH3·H2O in the precursor mixed solution can adjust the reaction speed of the pH value of the reaction system, thereby changing the growth rate of different crystal faces, and finally synthesizing single-substance Co particles of different morphologies. Among them, the block structure, the cut-angle columnar structure, and the nanorod structure have a larger surface area, which increases the reflection and scattering of the incident electromagnetic wave, effectively prolongs the propagation path of the electromagnetic wave, and brings more interface charge polarization, thereby improving the loss performance of the electromagnetic wave.

Hybrid organic-inorganic MXenes (h-MXenes) having amido, imido, alkoxy, or aryloxy surface terminating groups and methods for synthesizing the hybrid organic-inorganic MXenes are provided. The synthesis of h-MXenes having a broad scope of erminal organic functional groups is carried out via the displacement of halide atoms from halide-terminated MXenes by deprotonated primary organic amines or deprotonated alcohols.

The present invention belongs to the field of nanomaterial preparation, and provides a method for green preparation of fluorine-free MXene and its application in lithium-sulfur batteries, comprising: adding MAX to room temperature molten salt and stirring at a suitable temperature for a certain time; transferring the stirred mixed solution to a tube furnace, heating it to a certain temperature at different heating rates to react, and obtaining a solid powder. The obtained solid powder is added to a dilute hydrochloric acid solution, stirred at room temperature for a certain time, filtered, and vacuum dried to obtain a fluorine-free MXene material. The obtained fluorine-free MXene, Super P and PVDF are made into a uniform slurry and coated on the surface of a PP diaphragm, which is vacuum dried to obtain a MXene / PP composite film. The above-mentioned preparation process is simple, green and pollution-free, and fluorine-free MXene can be prepared; in addition, the prepared MXene / PP composite film material can be directly used as a diaphragm of a lithium-sulfur battery, which can inhibit the shuttle effect of polysulfide lithium and improve the reversible specific capacity and cycle stability of the lithium-sulfur battery.

The invention provides a water evaporation power generation device based on an MXene / filter paper composite film and a preparation method, and belongs to the technical field of water evaporation power generation. The preparation method comprises the following steps: adding FeCl2. 4H2O or FeSO4. 7H2O and ascorbic acid into a mixed solution of ethylene glycol and water, and stirring under a water bath condition to obtain an etching solution; slowly adding MAX powder into the etching solution, and carrying out magnetic stirring etching reaction to obtain a product solution; performing centrifugation, suction filtration and drying treatment on the product solution to obtain MXene solid powder; dissolving the solid powder in deionized water to form a solution, and carrying out suction filtration treatment on the solution on filter paper to obtain an MXene / filter paper composite film; the conductive parts are connected to the upper end and the lower end of the MXene / filter paper composite film, the water evaporation power generation device is obtained, the MXene stripping process is simple, the subsequent complex treatment process is not needed, and strong acid and virulent chemicals are not contained.

The invention discloses an MXene-coated PZS-C gel structure membrane electrode as well as a preparation method and application thereof, and belongs to the technical field of electrochemical uranium removal. Carrying out etching stripping or etching intercalation stripping on the MAX powder to form an MXene nanosheet suspension; the preparation method comprises the following steps: dissolving phosphonitrilic chloride trimer and 4, 4-dihydroxy diphenyl sulfone, adding triethylamine, and carrying out condensation reaction under the ultrasonic action to obtain microspherical PZS; the preparation method comprises the following steps: stirring and mixing an MXene nanosheet suspension and microspherical PZS, depositing the mixture on a substrate in a vacuum-assisted filtration manner to form a membrane body, and carrying out vacuum freeze drying and calcination on the membrane body to obtain the MXene-coated PZS-C gel structure membrane electrode which has good stability, fully exposes active sites, is used for electrochemical separation of uranyl ions, and has a good application prospect in electrochemical separation of uranyl ions. The maximum removal amount of the material reaches up to 3375.44 mg / g and is generally higher than that of other electrochemical uranium removal materials, and the material has a good application prospect.

The invention provides a preparation method and application of an MXene material, and the preparation method comprises the following steps: 1) sintering a mixture comprising an M source, an A source, a nitrogen source and a carbon source to obtain a precursor Mn + 1AXn; (2) the precursor is subjected to etching treatment, the MXene material Mn + 1XnTx is obtained, the etching treatment time is 1-3 h, a solution for etching treatment comprises a hydrogen fluoride solution with the mass fraction being 10-40%, and the temperature is 25-60 DEG C; the MXene material obtained by the preparation method shows strong absorption characteristics in different frequency bands, and can better meet the requirements on wave-absorbing materials at the present stage.

The invention provides an MXene membrane as well as a preparation method and application thereof, and the preparation method comprises the following steps: preparing a membrane from an antioxidant modified MXene material to obtain an initial membrane; and compounding and heating a thermal shrinkage sheet and the initial film to obtain the MXene film. The oxidation resistance and high temperature resistance of the MXene membrane are improved through surface modification, then the MXene membrane is combined with the thermal shrinkage sheet, the MXene membrane electrode with oxidation resistance, high temperature resistance and a micro-nano wrinkle structure is obtained, and the CDI adsorption rate and capacity are improved.