174results about "Selenium/tellurium compunds" patented technology

The invention discloses a method for preparing a single-layer tungsten diselenide nanoband based on a space confinement strategy. By changing the flow and the growth time of hydrogen, effective control on the width and the thickness of a nanoband can be realized. The method comprises the following steps: uniformly spraying tungsten trioxide powder to one substrate, then covering the substrate by the other substrate, and forming micro reaction space which is of a 'sandwich'-like structure. Growth of a tungsten diselenide nanoband is carried out by utilizing a constant-pressure chemical vapor deposition method; physicochemical characteristics of a one-dimensional transition metal chalcogenide strongly depend on suspension key types on the edge of the one-dimensional transition metal chalcogenide, metallic properties are displayed by an ultranarrow band, and conversion from the metallic properties to semiconductor properties can be displayed from the edge to the center of a wider band; the tungsten diselenide nanoband is widely applied to micro-nano photoelectric devices due to the special property; industrial production of the tungsten diselenide nanoband can be realized through an experimental method of the invention.

The invention discloses a ternary magnetic selenide and a preparation method of a single crystal of the ternary magnetic selenide, and relates to the technical field of crystal material preparation. The chemical formula of the ternary magnetic selenide is VCrSe3, and the ternary magnetic selenide can be prepared by taking a vanadium source, a chromium source and a selenium source in a specific proportion as raw materials and an iodine source as a transport agent through a chemical vapor transport method. The crystal structure of the VCrSe3 single crystal is a monoclinic phase (I2 / m), and phase transformation from antiferromagnetic to ferromagnetic and spin reorientation occur at low temperature, so that the VCrSe3 single crystal has application potential in the fields of spintronics, optoelectronics and the like; the large-size and high-quality VCrSe3 single crystal prepared by the method can provide a material for intrinsic physical property research and development of functional devices such as optoelectronic devices and spinning electrons.

The present invention relates to the working principle and production methods for the pre-expansion of sulfur and / or other chalcogenides such as selenium or tellurium, and / or a mixture of any two or more. The present invention further relates an electrode / cathode comprising sulfur and / or a mixture of sulfur allotropes, for example, crystalline, glassy, amorphous, and / or polymeric (e.g., β-, γ-, and / or ω-phasic) sulfur and / or a mixture of any two or more sulfur allotropes, wherein the sulfur is photonically / electronically / thermally pre-expanded to a state where it has a density equivalent to a metal sulfide, such as Li2S. The expansion is carried out before electrode / cathode fabrication for the realization of alkali and / or alkali earth metal / ion batteries, such as LiS batteries. The resulting pre-expanded chalcogenides such as sulfur has an artificially generated internal cavities / porosity in addition to an open / external porosity, wherein the internal cavities limits and / or compensates the expansion of sulfur further or expansion partially / negligibly during chemical / electrochemical reactions, such as lithiation or sodiation, with mono, di, and trivalent metal ions. A thus fabricated electrode / cathode comprising pre-expanded sulfur and / or chalcogenides allows precise control over density and volume fluctuations and withstands the chemical and electrochemical reactions that occur during battery operation. Additionally, leads to improved performance, and longevity and offers significant potential for further technological developments in this field.

The invention provides a P-type AgBi Se2 thermoelectric material and a preparation method thereof, and relates to the technical field of thermoelectric materials. According to the P-type AgBi Se2 thermoelectric material and the preparation method thereof, the chemical composition of a compound of the P-type AgBi Se2-based thermoelectric material is AgBi (1-x) MnxSe2, 0lt, xlt; and 0.7, the compound is a P-type thermoelectric material. The AgBi Se2-based thermoelectric material with P-type conductivity in a room temperature region is prepared by doping Mn element at the position of B element in a displacement manner and combining melting with a spark plasma sintering technology, and Mn atoms replace B lattice feeding points in a solid solution doping manner to cause mass and stress field changes, so that the lattice heat conductivity is further reduced, and the room temperature Seebeck coefficient of AgB Se2 can be changed from negative to positive. The increase of the doping amount of the manganese element can cause the improvement of the carrier concentration, and the power factor is remarkably improved, so that the ZT value of the P-type thermoelectric material in the room temperature region is remarkably improved, and the room temperature thermoelectric performance of the material is further improved. The invention is used for the P-type AgBi Se2 semiconductor material and the preparation method thereof.

The invention discloses a layered ternary selenide, a layered ternary selenide single crystal material and a preparation method of the layered ternary selenide single crystal material, and belongs to the technical field of crystal materials. The chemical formula of the layered ternary selenide is In2Ge2Se6, indium powder, germanium powder and selenium powder in a specific ratio are adopted as raw materials, synthesis of the layered ternary selenide In2Ge2Se6 single-phase material is achieved through the processes of high-temperature melting, heat preservation in a specific temperature interval and quenching, and the material has a narrow band gap and low heat conductivity and can be used for preparing the high-temperature-resistant layered ternary selenide In2Ge2Se6 single-phase material. And the thin-layer nanosheet single crystal material with the millimeter-level area can be prepared by a mechanical stripping method, and can be applied to the fields of semiconductor photoelectric devices, solar cells, thermoelectric devices and the like.

The invention is applicable to the technical field of carbon nanotube materials, and provides a cobalt-selenium co-doped carbon nanotube and a preparation method and application thereof, and the preparation method comprises the following steps: adding cobalt nitrate hexahydrate and a carbon nanotube into a methanol solution to obtain a solution A; dissolving 2-methylimidazole in a methanol solution to obtain a solution B; mixing the solution A and the solution B to form a purple precipitate, separating and washing the purple precipitate, and performing vacuum drying to obtain a ZIF-67 (at) CNT precursor; and putting the ZIF-67 (at) CNT precursor and selenium powder into a tubular furnace, raising the furnace temperature and preserving heat under argon flow, and then cooling to room temperature to obtain the Co-CoSe (at) CNT. According to the invention, a diatomic cobalt (Co) and selenium (Se) co-doped carbon nanotube (CNT) material is adopted as a main body material of sulfur, through a synergistic effect, the chemical adsorption capacity of the electrode material is remarkably enhanced, polysulfide is effectively captured, and excellent physical barrier performance is provided, so that the shuttle effect is further inhibited, and the long cycle life of the lithium-sulfur battery is prolonged.

The invention discloses a layered ternary selenide, a layered ternary selenide single crystal material and a preparation method thereof, and belongs to the technical field of crystal materials. The chemical formula of the layered ternary selenide is In2Ge2Se6, and indium powder, germanium powder and selenium powder with a specific ratio are used as raw materials. The synthesis of the layered ternary selenide In2Ge2Se6 single-phase material is achieved through high-temperature melting, insulation in a specific temperature range and quenching process. The material has a narrow band gap and low thermal conductivity, and its millimeter-level thin-layer nanosheet single crystal material can be prepared by mechanical stripping, which can be applied to semiconductor optoelectronic devices, solar cells, thermoelectric devices and other fields.

The invention relates to the field of batteries, in particular to an asphalt-based sodium ion electrode hard carbon negative electrode material and a preparation method thereof. The preparation method comprises the following steps: step 1, preparing hafnium silicide powder; step 2, preparing hafnium silicide amp; cobalt selenide composite microspheres; step 3, performing amp treatment on hafnium silicide; mixing the cobalt selenide composite microspheres, reduced graphene oxide and asphalt, and performing ball milling treatment to obtain an asphalt-based mixture; and 4, placing the asphalt-based mixture in a graphite furnace, introducing nitrogen as a protective gas, carrying out heating treatment, and cooling to obtain the hard carbon negative electrode material. According to the invention, hafnium silicide amp is used; the sodium ion electrode hard carbon negative electrode material is prepared by taking sodium selenide, cobalt selenide composite microspheres, reduced graphene oxide and asphalt as raw materials, and the negative electrode material not only has excellent performance in the aspects of specific capacity and coulombic efficiency, but also has the advantage of long cycle life.

The invention provides a p-type bismuth telluride-based material and a preparation method and application thereof, and belongs to the technical field of thermoelectric energy conversion materials. The p-type bismuth telluride-based material comprises a base material and a Bi element doped into crystal lattices of the base material; the base material comprises BiaSb1. 45Te3, and a is greater than or equal to 0.55 and less than or equal to 0.58. The thermoelectric performance and the mechanical performance of the material are improved by introducing the Bi element (electronegativity 2.02) which has a small electronegativity difference with the Te element (electronegativity 2.1), and the small electronegativity difference enables the Bi element in a matrix to have higher solubility, so that the carrier concentration (the doping of the Bi element mainly optimizes the carrier concentration) and the density of the material are improved; and the increase of the carrier concentration can improve the conductivity, so that the thermoelectric performance is improved.

The invention discloses a PtTe-Co (OH) 2 core-shell catalyst as well as a preparation method and application thereof, and belongs to the technical field of electrolyzed water catalysts. The morphology of the PtTe-coated Co (OH) 2 core-shell catalyst is in a sea cucumber-like shape, sea cucumber-like PtTe is used as a core, and amorphous Co (OH) 2 is used as a shell. The preparation method comprises the following steps: preparing sea cucumber-like PtTe by adopting a one-step wet chemical reduction method, and covering the surface of the PtTe with an amorphous Co (OH) 2 nano-sheet by adopting an in-situ growth method, so as to prepare the core-shell catalyst. The prepared PtTe-Co (OH) 2 core-shell catalyst has an excellent bifunctional characteristic, can drive an electrolyzed water reaction, and is simple in process, low in cost, safe in process, small in pollution and suitable for large-scale industrial production.

The invention relates to a preparation process of nano bismuth telluride, and belongs to the technical field of preparation of nano bismuth telluride, and the preparation process comprises the following steps: preparing a bismuth-based metal organic framework; carrying out coordination conversion on tellurate; calcining to remove organic conversion; and synthesizing bismuth telluride by a solvothermal method. The hexagonal flaky bismuth telluride with the average particle size of 200-300nm and reasonable particle size step-by-step is prepared through metal organic framework templating synthesis, the thermoelectric performance of the hexagonal flaky bismuth telluride is far better than that of a common bismuth telluride material, and the morphology and the particle size of the bismuth telluride are accurately controlled through metal organic framework templating accurate control so as to improve the thermoelectric performance of the bismuth telluride.

The invention relates to the technical field of lithium ion battery positive electrode materials, in particular to a lithium iron phosphate positive electrode material and a preparation method and application thereof.The preparation method comprises the following steps that 1, a lithium source, a sodium source, a magnesium source, an iron source and a phosphorus source are mixed to form a mixture, then a dispersing agent and an antioxidant are added, and the mixture is evenly mixed to obtain a mixed solution, performing hydrothermal reaction on the mixed solution to obtain a doped lithium iron phosphate precursor; 2) carrying out ball-milling mixing on an organic chiral material and the lithium iron phosphate precursor, and then carrying out high-temperature treatment in the presence of shielding gas to obtain a precursor A; 3) adding a copper source, a selenium source, alkali and a reducing agent into a solvent to obtain a mixed solution, and then adding the mixed solution into the precursor A for reaction to obtain a precursor B; and 4) in the presence of an initiator, carrying out polymerization reaction on the precursor B, graphene oxide, a chiral modifier and a monomer to obtain the lithium iron phosphate positive electrode material, the lithium iron phosphate positive electrode material provided by the invention can effectively improve the cycling stability.

The invention discloses a preparation method of a Bi2Te3-based thermoelectric material powder metallurgy precursor, which comprises the following steps of: performing hydrogen reduction on a thin strip sample or powder prepared from a zone melting bar of a bismuth telluride-based thermoelectric material at the temperature of 350-400 DEG C to obtain the Bi2Te3-based thermoelectric material powder metallurgy precursor. The Bi2Te3-based thermoelectric material powder metallurgy precursor can be used for preparing a bismuth telluride-based thermoelectric material for eliminating a donor-like effect through a powder metallurgy method. According to the method, powder can be prepared in the air, the donor-like effect generated in the powder preparation process can be eliminated through hydrogen reduction, the process of grinding and powder preparation in a protective atmosphere is avoided, the donor-like effect is eliminated at a lower temperature in a shorter time, the production process of the material can be simplified, the production cost can be saved, and the method is suitable for industrial production. And the optimal carrier concentration can be maintained while grains of the material are refined, and the optimal Seebeck coefficient is obtained.

To provide a semiconductor material capable of exhibiting applicability with respect to a near infrared region and a shortwave infrared region.SOLUTION: There is provided a semiconductor material including a substrate and a semiconductor thin film formed on the substrate. The semiconductor thin film comprises an Ru chalcogenide that comprises Ru, and Se and S which each are a chalcogen element and that is shown in the following formula, and the film thickness of the semiconductor thin film is 10 nm or more and 100 nm or less. The semiconductor material may exhibit responsibility to light in a wavelength region of 900 nm or more and 2,500 nm or less. (In the formula, x and y represent a ratio of the number of Se atoms and a ratio of the number of S atoms to the number of Ru atoms, respectively, x and y are real numbers satisfying 0<x<2.0 and 0<y<1.9, respectively, and x and y satisfy 1.9<x+y<2.0.)SELECTED DRAWING: Figure 2

The invention relates to the technical field of cold storage, and particularly discloses a cold storage material and a preparation method and application thereof. Wherein the cold storage material comprises a Gd2O2Se crystal. The cold storage material comprises the Gd2O2Se crystal, and the Gd2O2Se crystal has phase transformation near 6.22 K, has relatively large specific heat in a temperature range of 1-10 K, has a remarkable magnetothermal effect and can be used as a cold storage material at a liquid helium temperature.

The present invention discloses a preparation method and application of a class of silver nanocluster-embedded niobium polyacid crystalline materials with immunological activity, belonging to the technical field of pharmaceutical synthesis. The chemical formula of the silver nanocluster-embedded niobium polyacid crystalline materials with immunological activity is L x [Ag 30 Cl y (SeO3) (8‑y) (SiNb 18 O 54 )6]·zH2O; wherein, L is a counter cation or cationic group, 1 < x ≤ 70, 0 < y ≤ 8, 1 < z ≤ 150; the overall cluster structure of the silver nanocluster-embedded niobium polyacid crystalline materials with immunological activity is composed of the [Ag 30 Cl y (SeO3) (8‑y) (SiNb 18 O 54 )6] anion cluster and the corresponding counter cation or cationic group; this material has good water solubility and stability under physiological conditions, has high cytotoxicity and selectivity for tumor cells, especially CT26 colon cancer cells, can induce immunogenic death of tumor cells and activate the body's immune system, has little toxic and side effects on normal cells and organs, and has better biosafety than the traditional chemotherapeutic drug doxorubicin, and can be used as an anti-tumor immunotherapy drug in the biomedical field.

According to the invention, a one-pot synthesis strategy is adopted, a polyoxometallate with high proton conductivity and a pure inorganic three-dimensional frame structure is successfully synthesized by accurately controlling the reaction temperature, the pH value and the proportion of raw materials, and the chemical formula of the polyoxometallate is [H2N (CH3) 2] 8K3Na2H4 [Se4W35Ce2O124 (H2O) 4] Cl. 22H2O; based on the structural characteristics, the proton conductivity is further systematically tested under different temperature and humidity conditions; then, Arrhenius fitting is performed on experimental data, and activation energy of proton migration is calculated, so that a proton conduction mechanism is deeply discussed; the polyoxometallate prepared by the invention is of a pure inorganic three-dimensional frame structure, is completely composed of metal-oxygen bonds, and has important structural innovation significance; in addition, the polyoxometallate has the advantages of high proton conductivity, simple preparation process, good chemical stability and the like, so that the polyoxometallate becomes a solid proton conduction material with great application potential.

Provided are a novel magnesium composite oxide or calcium composite oxide, and a method for producing same.　The production method is for producing a composite oxide containing magnesium or calcium, and includes: a heating step for heating a precursor compound at a temperature of 500ºC or lower in the presence of a salt that contains magnesium or calcium; and a washing step for washing with a washing liquid that includes water after the heating step. A combination of the precursor compound and the composite oxide is any of (A) to (E).

The invention provides a layered Van der Waals material with full-compensation ferrimagnetism and a topological Hall effect as well as a preparation method and application of the layered Van der Waals material. The chemical formula of the material is MnxCrTe2, wherein 0 lt; and x is 1. The material provided by the invention has a wide compensation temperature range, a large magnetoresistance effect, anisotropy and a topological Hall effect, is a CrTe2 intercalation ferromagnetic material doped in different proportions, and can realize optimization and continuous adjustability of performances such as magnetism, Curie temperature and Hall parameters of the material through regulation and control of mechanisms such as the doping proportion, the temperature and the magnetic field; and a material basis is provided for researching the application of the Mn intercalation CrTe2 crystal material in the field of magnetic induced storage.

The invention relates to a preparation method of an ammonium ion intercalation two-dimensional material, which comprises the following steps: by taking a two-dimensional material single crystal as a raw material and ammonium iodide as an intercalation agent, putting the two-dimensional material single crystal into an ammonium iodide solution, heating, cooling, cleaning, and drying in vacuum to obtain an ammonium ion intercalation two-dimensional material compound. The preparation method is simple, quick, green, environment-friendly, high in efficiency and low in cost; the prepared ammonium ion intercalation type two-dimensional material has great application prospects in the aspects of energy storage, catalysis, ion exchange and the like.

The invention relates to an electromagnetic composite absorbent with a multi-interface hollow structure and a preparation method thereof. According to the technical scheme, metal salt, isopropanol and glycerinum are mixed and stirred twice, dispersion liquid is obtained, and the metal element in the metal salt is Mn or Mo or a mixture of Mn and Mo; putting the dispersion liquid into a high-pressure reaction kettle, carrying out hydrothermal reaction, drying, and carrying out annealing treatment to obtain hollow spheres; mixing water with the Tris buffer solution to obtain a mixed solution; dissolving hollow spheres in the mixed solution to obtain a turbid liquid; then mixing the turbid liquid with a carbon-nitrogen material, carrying out auto-polymerization coating, carrying out solid-liquid separation, and drying to obtain a hollow sphere with a core-shell structure; and mixing the hollow sphere with the core-shell structure with selenium powder, and carrying out heat treatment to prepare the electromagnetic composite absorbent with the multi-interface hollow structure. The method has the characteristics of high reaction safety, low absorbent filling, wide effective absorption bandwidth, high intrinsic loss and high absorption strength.

The application relates to application of Bi2O2Se in a photocatalytic nitrogen fixation reaction and belongs to the technical field of photocatalytic nitrogen reduction. The BOS catalyst with intrinsic weak hole oxidation capacity realizes efficient and stable photocatalytic ammonia synthesis without a sacrificial agent. The BOS has an optimized narrow band gap structure and a unique straddling energy band arrangement, the valence band position is shallow, the hole oxidation capacity is weak, the oxidation degradation of NH4 + Can be effectively inhibited, and the conduction band position is suitable, so that the thermodynamic driving force of nitrogen reduction is ensured. The catalyst has excellent light absorption capacity in a wide spectral range (extending to the near-infrared region), and the apparent quantum efficiency reaches 0.12% at a wavelength of 700 nm. The ammonia synthesis rate of the BOS without a sacrificial agent reaches 61 muM.h ‑1 -1, which is 8.3 times and 2.8 times that of carbon nitride and cadmium sulfide, and the catalyst maintains high activity in an air atmosphere, has excellent oxygen compatibility and cycle stability.

The present invention provides a transistor-type photodetector with high sensitivity and easy startup, which includes a substrate. A gate is disposed on the substrate, and an insulating layer is wrapped on the gate. An active layer is disposed on the insulating layer, and the active layer includes an indium gallium zinc oxide thin film, a two-dimensional tungsten diselenide layer, and a lead selenide thin film. A source electrode is disposed at the left end of the lead selenide thin film, and a drain electrode is disposed at the right end. The present invention can overcome the lattice defect problems of the indium gallium zinc oxide thin film and the lead selenide thin film, improve the photocurrent of the optoelectronic device while also improving the sensitivity, ensure excellent electrical conductivity while also providing good stability, and improve the overall performance of the optoelectronic device. This phototransistor has the remarkable characteristics of high sensitivity and easy startup, and has a wide range of applications.

The invention belongs to the technical field of two-dimensional nano materials, and relates to an MXene material as well as a preparation method and application thereof. The invention provides a novel and efficient MXene material preparation method which is characterized in that a precursor MAX phase material, a chalcogenide element simple substance and an iodine simple substance are mixed and then subjected to a high-temperature reaction in a vacuum environment. According to the method, a chalcogenide and iodine are ingeniously utilized to generate iodide (such as SeI2 or TeI2) with strong oxidizing property in situ at a high temperature, the chalcogenide in a high oxidation state can selectively oxidize A-site atoms (such as Al) in an MAX phase, the A-site atoms are converted into volatile iodide (such as AlI3) and escape from a system, and therefore selective stripping of an A layer is achieved; and a two-dimensional Mn + 1Xn skeleton is formed. Meanwhile, the reduced chalcogenide is directly bonded to the surface of MXene as a terminal group, and the functionalized MXene material with the chalcogenide terminal group (-S,-Se or-Te) is synthesized in one step.

The application relates to a preparation method of a ternary alloy nanoflower and an organic hybrid composite film thereof, and belongs to the technical field of nanometer materials and functional films. BiCl3, SbCl3 and TeO2 are dissolved in ethylene glycol, NaOH and PVP K30 are added, stirring is carried out at room temperature until a clear solution is obtained, the solution is transferred to a reaction kettle, and reaction is carried out in a blast drying oven; after cooling, centrifugal washing is carried out; after drying, a Bi-Sb-Te alloy nanoflower is obtained; the Bi-Sb-Te alloy nanoflower is mixed with a PEDOT:PSS aqueous solution; a conductive enhancer is added, ultrasonic dispersion is carried out to form a uniform slurry; the slurry is deposited on the surface of a glass substrate by using a drying machine through a flow casting method; after annealing, the film is peeled off, vacuum drying is carried out, and a flexible thermoelectric composite film is formed. Through the establishment of a trinity technology of "nanoflower morphology design-in-situ interface optimization-low temperature solution process", the problems of poor flexibility of traditional thermoelectric materials, nanocomposite interface failure and unsustainable high-temperature process are solved.

The invention relates to the technical field of thermoelectric materials, in particular to a Bi2SeS2-based thermoelectric material and a preparation method and application thereof, the Bi2SeS2-based thermoelectric material takes Bi2SeS2 as a matrix, and the matrix is doped with a copper element and silicon carbide as a nano composite phase. According to the invention, the electric transport performance and the heat transport performance of the material are synchronously optimized through a synergistic strategy of Cu doping and SiC nano-compounding; cu doping effectively improves the carrier concentration and conductivity, SiC nano-compounding introduces a large number of nano-interfaces, the SiC nano-compounding and the point defects generated by Cu doping jointly construct a point defect-nano-interface multi-scale phonon scattering mechanism, and the lattice thermal conductivity is remarkably reduced. Moreover, the process for preparing the Bi2SeS2-based thermoelectric material is simple, the cost is low, the thermoelectricity of the Bi2SeS3 material at 773 K is successfully improved to 0.83, and a reliable way is provided for industrial application of the Bi2SeS2-based thermoelectric material.

The invention relates to a mercury-containing acid mud efficient recovery method and device based on difference frequency resonance coupling. The high-efficiency mercury-containing acid mud recovery method based on difference frequency resonance coupling comprises the following steps: step 1, acid mud pretreatment: crushing, screening and drying mercury-containing acid mud; 2, coupled field leaching is conducted, specifically, a product in the step 1 is conveyed into a reaction kettle, stirring is conducted after an oxidizing agent is added, an acid mud turbid liquid is obtained, an oxidation-reduction reaction is conducted through catalysis of a difference frequency resonance coupled field formed by two frequency-adjustable ultrasonic waves, and the difference frequency adjusting range delta f is 6-10 kHz; step 3, carrying out solid-liquid separation; leaching liquid containing mercury and selenium is obtained. According to the scheme provided by the invention, the standing wave effect can be formed through the difference frequency, and the crushing efficiency of the cavitation bubbles is improved, so that the oxidation reaction speed of the mercury-containing acid mud turbid liquid is improved; secondly, through the adjustable frequency, the situation that the ultrasonic frequency is not matched with the mercury ion concentration and the turbid liquid temperature, and consequently ultrasonic energy waste is caused is avoided.

This solid electrolyte has: a first crystallite which is formed into a primary particle and has a first crystal structure; a second crystallite which is formed into the same primary particle as the first crystallite and has a second crystal structure that is different from the first crystal structure; and an amorphous phase. The first crystallite and the second crystallite each contain lithium, the first crystal structure is a hexagonal crystal structure, the second crystal structure is an orthorhombic crystal structure, and the crystallite size of the first crystallite and the crystallite size of the second crystallite are both 50 nm or less.

This invention relates to the field of crystal material preparation technology, specifically to a ternary layered selenide Ge 0.85 Bi 2.15+x Se4 semiconductor material and its preparation method. The preparation method includes the following steps: according to the chemical formula Ge... 0.85 Bi 2.15+x The molar ratio of germanium powder, bismuth powder, and selenium powder in Se4 is weighed, where 0 ≤ x ≤ 0.06. The weighed raw materials are mixed evenly and placed in a quartz tube. The quartz tube is then sealed under vacuum. The vacuum-sealed quartz tube is placed in a heating furnace and heated from room temperature to 900-950℃, held at this temperature for 12-24 hours. After the holding period, the quartz tube is removed from the heating furnace and quenched. The quenched and cooled quartz tube is then placed back in the heating furnace and heated from room temperature to 540-560℃, held at this temperature for 3-5 days for annealing, thus obtaining the ternary layered selenide Ge. 0.85 Bi 2.15+x Se4 semiconductor material. This invention successfully solves the technical problem of obtaining a single phase in the GeBi2Se4 system by precisely controlling the Ge / Bi ratio and employing high-temperature quenching and low-temperature long-time annealing processes.

The invention discloses an n-type lead selenide-based thermoelectric material and a preparation method and application thereof, and belongs to the technical field of energy material preparation. The chemical formula of the n-type lead selenide-based thermoelectric material is Pb < 1-x > CrxSe < 0.998 > Cl < 0.002 > (x is more than or equal to 0.002 and less than or equal to 0.006); according to the material, high-purity raw materials are mixed according to the molar ratio in the chemical formula, and the target lead selenide-based thermoelectric material is prepared by combining a high-temperature smelting method with a discharge plasma sintering method. Through double doping of Cr and Cl elements, the conductivity of the n-type lead selenide-based thermoelectric material is greatly improved and the thermal conductivity of the n-type lead selenide-based thermoelectric material is reduced through the synergistic effect of the Cr and Cl elements, the prepared Pb0. 996Cr0. 04Se0. 998Cl0. 002 material has a high thermoelectric figure of merit at the high temperature of 723 K, and the average thermoelectric figure of merit at the medium and low temperature of 300-673 K reaches 1.037. The thermoelectric figure of merit of the n-type lead selenide-based thermoelectric material can be greatly improved, the conversion efficiency of a thermoelectric power generation device can be improved, and the industrial application of the thermoelectric power generation device can be expanded.