87 results about "Tungsten diselenide" patented technology

The invention proposes a method for growing a substrate-modified large-size monolayer molybdenum disulfide film through chemical vapor deposition. Ammonium sulfide serves as a substrate surface modifying agent; a nucleation rate is controlled through such methods as control of a concentration of the modifying agent, a dipping time and a cleaning method; and a film thickness is controlled through such methods as control of a growing temperature, a growing time and an air flow of the chemical vapor deposition. The method can efficiently grow the large-size monolayer molybdenum disulfide film under the condition of a relatively lower growing temperature on the basis of traditional growth chemical vapor deposition equipment. The method for growing large-size monolayer molybdenum disulfide, provided by the invention, is suitable for the growth of large-size monolayer tungsten disulfide, molybdenum diselenide, tungsten diselenide and the like similar to two-dimensional semiconductor materials in structure.

The invention discloses a preparation method of a tungsten diselenide nanosheet, and belongs to the technical field of nanometer material preparation. The preparation method comprises the following steps of dissolving sodium borohydride into an organic solvent, and successively adding selenium powder and sodium tungstate to prepare a mixed solution; transferring the mixed solution to a reaction kettle, and performing reaction for 6 to 48 hours at 200 DEG C to 240 DEG C; after the temperature of the reaction kettle is naturally cooled to the room temperature, collecting black products through suction filtration; washing the product by deionized water and ethyl alcohol; freezing and drying the washed product to obtain the tungsten diselenide nanosheet. The invention provides the method for synthesizing the tungsten diselenide nanosheet in one step by a solvothermal method for the first time. The preparation method has the advantages that the raw materials are green and environment-friendly; the cost is low; the yield is high; the reaction condition is mild; the scale production can be realized. The high-crystallization tungsten diselenide nanosheet prepared by the method has the advantages that the size is great; the layer number is small; the distribution is uniform; the specific surface area is high; high application prospects are realized in the fields of catalysis, energy storage and the like.

The invention discloses a method for preparing tungsten diselenide nano sheets, comprising the following steps of: evenly mixing tungsten powder and selenium powder in a certain mol ratio; heating and reacting the mixture under protection of argon, and cooling to obtain the tungsten diselenide nano sheets. The tungsten diselenide nano sheet is of an inorganic nano sheet laminated structure; the tungsten diselenide nano sheet has excellent dispersion performance and friction performance in base oil and polymer compounds; the tungsten diselenide nano sheet is simple in preparing method, safe, environment friendly, high in production rate, low in cost and suitable for large-scale industrial production.

The invention relates to a graphene / WSe2 / NiFe-LDH aerogel and a preparation method thereof. The preparation method comprises following steps: mixing graphene oxide sheet dispersion liquid and WSe2 nano sheet dispersion liquid; adding at least one of a reducing agent, a crosslinking agent, and a pH adjuster, evenly mixing, carrying out reactions to obtain graphene / WSe2 hydrogel, freeze-drying the hydrogel to obtain graphene / WSe2 aerogel; soaking the graphene / WSe2 aerogel in NiFe-LDH nano sheet dispersion liquid to prepare graphene / WSe2 / NiFe-LDH hydrogel, and carrying out freeze-drying to obtaingraphene / WSe2 / NiFe-LDH aerogel. The provided N,S co-doped graphene / WSe2 / NiFe-LDH (N,S co-doped graphene / tungsten diselenide / NiFe-LDH) preparation method is simple, the cost is low, and the preparedN,S co-doped graphene / WSe2 / NiFe-LDH has excellent electrochemical properties such as large specific capacitance, good cycle performance, small internal resistance, and the like.

The invention belongs to the field of two-dimensional materials. The invention discloses a method for growing a multilayer tungsten diselenide single crystal by molten salt assisted chemical vapor deposition. According to the method, a preset temperature condition is utilized, when a small reaction chamber is under the preset temperature condition, a halide can be molten and react with a tungstensource material to generate an intermediate product with the melting point lower than that of the tungsten source material, and a carrier gas flow can carry gaseous selenium generated by a selenium source material and gaseous tungsten generated by the intermediate product to grow the multi-layer tungsten diselenide single crystal on a substrate based on the chemical vapor deposition principle. According to the invention, key reaction participants and the reaction chamber of the preparation method are improved, halide and a tungsten source material are mixed to participate in reaction, halide molten salt and the tungsten source material react to generate an intermediate product with the melting point lower than that of the tungsten source material, chemical vapor deposition can be effectively controlled to grow the multilayer tungsten diselenide single crystal, the controllability is good, and a multilayer tungsten diselenide single crystal with a large size can be prepared.

The invention discloses a coating material for preventing an engine crankshaft from being locked, and a preparation method and an application method of the coating material. The coating material comprises the following raw materials in parts by weight: PAG (Polyalkylene Glycol ethers) polyether base oil, modified plant-based synthetic ester oxide sunflower oil, epoxy resin, organic molybdenum, tungsten disulfide powder, tungsten diselenide powder, carbon monofluoride powder, polyphenyl, a fire retardant, an antiwear agent and an antioxidant. The coating material is coated on a crankshaft neck surface and / or bearing bush surface between a crankshaft neck and a bearing bush (tile), so that a protective coating which is lubricant enough, and not easy to wash off or damage, and can bearing extremely high temperature is provided under the condition that the engine oil cannot provide effective lubricating due to poor quality, or cannot provide an enough lubricating effect between the crankshaft and a connecting rod due to reduction of the engine oil, the coating material has excellent waterproof properties, anti-rust characteristics, anti-corrosion property, and micro-grinding resistance on metal parts, can form solid dry film lubrication under the environment above 200 DEG C, and can play the roles in lubricating and preventing metal from being locked by sintering at the temperature which can be up to 1400 DEG C, and the locking phenomenon between the crankshaft and the connecting rod caused by dry friction between the tile and the crankshaft is effectively avoided.

The invention discloses a method for preparing a tungsten diselenide nanoflower, and belongs to the technical field of nanometer material preparation. The method comprises the following steps: dissolving H2SeO3 in an organic solvent and mixing uniformly, and adding Na2WO4 2H2O to prepare a mixed solution while stirring; transferring the mixed solution into a reaction kettle and reacting at a temperature in the range of 180-240 DEG C for 12 hours to 48 hours; after the temperature of the reaction kettle is naturally cooled to room temperature, collecting a black product by suction filtration, washing the product with deionized water and ethanol respectively, and drying in vacuum to obtain tungsten diselenide nanoflower. The method for synthesizing the tungsten diselenide nanoflower by one step through a solvothermal method is firstly provided. The preparation method provided by the invention has the advantages of simple process, easy obtaining of raw materials, low cost, mild reaction conditions and the like.

The invention discloses a preparation method of a tungsten diselenide nano-clathrate. The preparation method is as follows: tungsten powder and selenium powder which are in a certain molar ratio and graphite are used, absolute alcohol is added to prepare raw material mixture, the mixture is processed to form paste, and the paste performs solid-phase synthesis under a certain condition to obtain the tungsten diselenide nano-clathrate with a core-shell structure. The product has uniform size and large specific surface area; the product still has good mechanical properties and wear resistance under extreme conditions such as high temperature and high pressure and has good dispersibility in macromolecular composite and other composites; and the product is a lubricating material with good performance, has simple preparation process, controllable parameters and safe and environmentally friendly production process and is particularly suitable for large-scale industrial production.

The invention relates to a metal structure tungsten diselenide / redox graphene composite structure and a preparation method thereof. Firstly, a precursor aqueous solution of a WSE2 film is prepared; a monolayer graphene oxide aqueous solution and citric acid are added into the precursor aqueous solution of the WSE2 film to obtain a WSe2 / RGO precursor aqueous solution; then, after hydrothermal treatment at 165-180 DEG C, a thin-film metal structure tungsten diselenide / redox graphene composite structure is obtained on a polyethylene naphthol substrate inserted into the WSe2 / RGO precursor aqueous solution, and a precipitate in a residual solution after the hydrothermal treatment is filtered, washed and dried to obtain a powder metal structure tungsten diselenide / redox graphene composite structure. According to the invention, the preparation of metal structure tungsten diselenide can be realized through a one-step synthesis process through a hydrothermal method, and the preparation method is not only simple in process, but also has the excellent characteristics of low cost of used raw materials and equipment, low energy consumption, high efficiency and the like.

The invention belongs to the field of battery materials, and particularly discloses a polymer@two-dimensional material modified layered double hydroxide composite diaphragm material which comprises apolymer material and an active material compounded in the polymer film material, wherein the active material is the two-dimensional material modified layered double hydroxides and comprises layered double hydroxides and a two-dimensional material growing on the surfaces of the layered double hydroxides in situ; the two-dimensional material is at least one of molybdenum diselenide, tungsten diselenide, molybdenum disulfide and tungsten disulfide. The invention also provides preparation of the diaphragm and application of the diaphragm in a lithium-sulfur battery. The material is advantaged in that the brand-new material provided by the invention can effectively solve the boundary effect of a two-dimensional material, can open more active sites, avoids agglomeration, and can unexpectedly improve the performance of the battery diaphragm by adding the brand-new material into the battery diaphragm, for example, the sulfur loading capacity and the catalytic degradability to polysulfide compounds are improved, and the performance of the battery is improved.

Bulk direct transition metal dichalcogenide (TMDC) may have an increased interlayer separation of at least 0.5, 1, or 3 angstroms more than its bulk value. The TMDC may be a bulk direct band gap molybdenum disulfide (MoS2) or a bulk direct band gap tungsten diselenide (WSe2). Oxygen may be between the interlayers. A device may include the TMDC, such as an optoelectronic device, such as an LED, solid state laser, a photodetector, a solar cell, a FET, a thermoelectric generator, or a thermoelectric cooler. A method of making bulk direct transition metal dichalcogenide (TMDC) with increased interlayer separation may include exposing bulk direct TMDC to a remote (aka downstream) oxygen plasma. The plasma exposure may cause an increase in the photoluminescence efficiency of the TMDC, more charge neutral doping, or longer photo-excited carrier lifetimes, as compared to the TMDC without the plasma exposure.

The invention relates to a preparation method of a molybdenum disulfide / tungsten diselenide vertical heterojunction. The method comprises the steps: firstly preparing a molybdenum disulfide thin layeron a silicon dioxide / silicon substrate by a chemical vapor deposition method and then depositing a tungsten diselenide thin layer on the substrate by the chemical vapor deposition method and realizing the vertical heterojunction formed by the two materials at the growth temperature of 600-700 DEG C under the assistance of NaI. The preparation method of the molybdenum disulfide / tungsten diselenidevertical heterojunction material is simple in process, the addition of low melting point salts to the raw materials with combination of the mature basic process can avoid atomic substitution, thermaldecomposition, alloying and other unfavorable factors of the underlying transition metal disulfides (TMDCs) and realize the growth of the high-quality atomic steep-interface two-dimensional heterojunction. The present invention provides a new growth mechanism that enables a more in-depth understanding of the growth process of the TMDCs vertical heterojunction in terms of nucleation and dynamics so as to define a multifunctional material platform for basic research and potential device application.

The invention discloses a method for preparing a tungsten diselenide semiconductor film on an FTO substrate. The method for preparing the tungsten diselenide semiconductor film on the FTO substrate is characterized in that the method comprises the following steps that S1, a reaction precursor solution is prepared, specifically, a solvent, a selenium source, a tungsten source and a reductive agent are evenly mixed to prepare the reaction precursor solution; S2, FTO conductive glass is pretreated, specifically, the FTO conductive glass is subjected to preliminary surface washing treatment; and S3, the tungsten diselenide semiconductor film is prepared, specifically, the treated FTO conductive glass after the step S2 makes contact with the reaction precursor solution prepared in the step S1, and after a sufficient reaction under a high-temperature and high-pressure condition, the tungsten diselenide semiconductor film is prepared on the FTO conductive glass. The method for preparing the tungsten diselenide semiconductor film has the advantages of being simple in preparing technology, low in cost and capable of obtaining the tungsten diselenide semiconductor film which is even in physical phase, good in crystallization and high in purity; and the WSe2 semiconductor film has good prospects in manufacturing of dye-sensitized solar cells and thin-film solar cells.

The invention specifically relates to a thermal insulation cement slurry for the well cementation of low-temperature sections of deep geothermal wells and a preparation method thereof. The thermal insulation cement slurry for the well cementation of low-temperature sections of deep geothermal wells is prepared from the following materials in percentage by weight: 15 to 25 percent of oil well cement, 15 to 25 percent of ultrafine oil well cement, 4 to 7 percent of tungsten diselenide, 2 to 5 percent of nano-silica, 4 to 7 percent of hollow glass microspheres, 1 to 4 percent of early strength agent, 1 to 2 percent of fluid loss reducer, 0.2 to 0.6 percent of dispersant, 1 to 3 percent of glass wool fibers, 5 to 10 percent of silicate and the balance of water. The preparation method includes the following steps: the oil well cement, the ultrafine oil well cement, the tungsten diselenide, the nano-silica, the hollow glass microspheres, the early strength agent, the fluid loss reducer, the dispersant and the water are stirred to be uniformly mixed, the glass wool fibers and the silicate are then sequentially added, and stirring is carried out for uniform mixing. The thermal insulation cement slurry for the well cementation of low-temperature sections of deep geothermal wells disclosed by the invention has good thermal insulation capability and the advantages of low density, early strength, low moisture loss, easiness in pumping and the like, and the various property indexes can fully meet the requirement of on-site well cementation.

The invention discloses a molybdenum-doped tungsten diselenide nanosheet serving as an anti-fraction additive and a preparation method thereof. The molybdenum-doped tungsten diselenide nanosheet serving as the anti-fraction additive is the nanosheet of which the thickness is 50 nm and both the length and the width are below 500 nm. In the invention, the molybdenum-doped tungsten diselenide nanosheet is prepared by using ball milling-heating solid-phase reaction; the preparation process is simple, the parameters are easy to control, and the production process is safe and environmentally-friendly. Due to the lamellar structure, the prepared molybdenum-doped tungsten diselenide nanosheet can be used as a solid lubricant, can also be used as the anti-friction additive for lubricating oil and grease and has broad development prospect in the field of engineering application. The molybdenum-doped tungsten diselenide nanosheet serving as the anti-fraction additive and the preparation method thereof have the advantages of excellent practicability, excellent economic prospect and capability of producing excellent social benefit.

The invention particularly relates to a gallium oxide-two-dimensional P-type Van der Waals tunneling transistor, a dual-band photoelectric detector and a preparation method, and solves the technical problem that PN junction deep ultraviolet-infrared dual-band detection of the tunneling transistor and gate voltage modulation cannot be realized simultaneously due to lack of P-type doping of Ga2O3 in preparation of an existing UWBG material transistor / photoelectric detector. The transistor and the photoelectric detector comprise a back gate electrode, a dielectric oxide layer, a gallium oxide layer, a gallium oxide electrode forming ohmic contact, a P-type two-dimensional material layer, a P-type two-dimensional material electrode forming ohmic contact, and a dielectric passivation layer. The gallium oxide layer and the P-type two-dimensional material layer are partially overlapped to form a heterojunction; the gallium oxide layer is an unintentionally doped or doped Ga2O3 quasi-two-dimensional crystal film; and the P-type two-dimensional material layer is black phosphorus or a beta-phase tellurium elementary substance or a 2H-phase molybdenum ditelluride or tungsten diselenide or platinum diselenide film. In addition, the invention also provides a preparation method of the transistor and the dual-band photoelectric detector.

The invention provides a two-dimensional horizontal homojunction, a self-driven logic photoelectric switch and a preparation method of the self-driven logic photoelectric switch, and belongs to the technical field of semiconductor photoelectricity. The photoelectric switch comprises two-dimensional tungsten diselenide, a silicon / silicon dioxide insulating substrate, boron nitride, an indium metaln-type doped source layer and a gold metal p-type doped source layer. P-type doping is carried out on two-dimensional tungsten diselenide by utilizing a gold electrode, n-type doping is carried on thetwo-dimensional tungsten diselenide by utilizing an indium electrode, and the two-dimensional tungsten diselenide level p-n homojunction is constructed. Boron nitride and insulating silicon are usedas a gate dielectric layer, and silicon is used as a gate electrode. The two-dimensional tungsten diselenide material used as a photosensitive material generates photo-generated electron hole pairs under illumination, and gate voltage is applied to the silicon substrate to regulate the rectification direction of a homojunction, so that the flowing direction of photo-generated electron holes is controlled, and the effect of the logic photoelectric switch is achieved.

The invention discloses a method for constructing a two-dimensional schottky heterojunction model based on germanene. The method comprises the following steps: establishing a WSe2 bulk material model;establishing a Germanene model; carrying out crystal face uniform cutting on the WSe2 body material model to obtain a single-layer WSe2, and carrying out crystal face uniform cutting on the Germanenemodel to obtain a Germanene thin layer; establishing a supercell of Germanene according to the Germanene thin layer, establishing a supercell of WSe2 according to the single-layer WSe2, and vertically superposing the supercell of Germanene on the supercell of WSe2 to obtain a Germanene / WSe2 heterojunction model. Germanene is vertically stacked on single-layer tungsten diselenide for the first time, and lattice parameters, energy band structures, thermodynamic stability, electron effective mass and the like of supercells are calculated.

The invention discloses a tungsten diselenide and metal vertical schottky junction self-driven photoelectric detector and preparation and belongs to the technical field of material application. The tungsten diselenide and metal vertical schottky junction self-driven photoelectric detector comprises an insulating substrate, a tunneling layer, a metal electrode and a tungsten diselenide nanosheet. Self-driven detection of a device is achieved by using a photovoltaic effect generated by a schottky junction formed by tungsten diselenide and metal under illumination, the light accepting area of a junction area is expanded through a vertical structure, an adjustable detection wavelength range is achieved through controlling the number of tungsten diselenide layers, increase of reverse current isinhibited through the tunneling layer, the sensitivity of the detector is improved and the response time is prolonged.

The invention discloses a photoelectric device based on a rhenium disulfide / tungsten diselenide (ReS2 / WSe2) heterojunction and a preparation method, and belongs to the technical field of material application. The photoelectric device comprises a P-type silicon substrate, a silicon dioxide insulating layer, a heterojunction formed by single-layer ReS2 and WSe2, a drain electrode and a source electrode, wherein the source electrode, the drain electrode and the single-layer ReS2 and WSe2 are all located on a silicon dioxide / silicon (SiO2 / Si) substrate, and Si is a grid electrode. The invention further discloses a simple method for preparing the photoelectric detection device. The photoelectric detection device realizes a wide barrier region and suppresses the influence of a defect state in ReS2 to the detector, thereby improving the response time of the detector.

The invention discloses high-performance ceramic and a preparation method thereof. The high-performance ceramic is prepared from raw materials in parts by weight as follows: 6-8 parts of zinc oxide, 30-40 parts of high-potassium sand, 3-5 parts of ultrafine molybdenum powder, 1-2 parts of cobalt sulfide, 40-60 parts of hauynite, 1-3 parts of sodium bicarbonate, 3-5 parts of tungsten diselenide, 8-15 parts of Suzhou clay, 0.5-1 part of tartaric acid, 1-2 parts of bismuth subcarbonate, 3-5 parts of tin antimony oxide, 4-6 parts of carboxymethylcellulose, 1-3 parts of nano magnesium titanate, 1-2 parts of polyethylene wax, 6-7 parts of a reinforcing agent and a proper amount of absolute ethyl alcohol. The ceramic is low in production cost, excellent in comprehensive performance, high in strength and good in chemical stability; components such as the hauynite, the ultrafine molybdenum powder and the like are added, so that the ceramic is good in fire resistance and low in thermal expansion rate; components such as the tungsten diselenide, tin antimony oxide, the nano magnesium titanate and the like are added, thus, the strength and the fire resistance of the ceramic are further enhanced, and the ceramic has the reliable safety during usage.

The invention discloses an MSe2 thin film material, a preparation method and application thereof, and belongs to the technical field of thin film material preparation. The MSe2 thin film material comprises a base, and an MSe2 thin film loaded on the base, wherein the MSe2 thin film comprises at least one of a tungsten diselenide thin film and a molybdenum diselenide thin film. According to the MSe2 thin film material provided by the invention, the tungsten diselenide thin film and / or the molybdenum diselenide thin film horizontally grows on the surface of stainless steel in a layered structure, and each layer of thin films are closely packed in a close-packed hexagonal structure to form a monomolecular layer with good stability; each layer of single molecules are combined mutually into a layered semiconductor material by depending on van der waals force; the sliding between the layered semiconductor materials is easy; and the MSe2 thin film material has relatively low friction coefficient in the friction material application.

The invention discloses a method for synthesizing a single-layer transition metal chalcogenides, and belongs to the technical field of preparation of nano materials. The method comprises the followingsteps that molybdenum diselenide powder and tungsten diselenide powder are taken as raw materials and a gas mixture of inert gases Ar (95%) and H2 (5%) is taken as carrier gas; a PVD method is adopted to take an sole temperature region of a high-temperature tubular vacuum oven as both a powder melting and evaporating region and a region for a substrate to bear sample deposition; and a single-layer MoSe2 sample and a single-layer WSe2 sample are synthesized on a Si / SiO2 substrate and a sapphire substrate. The sample prepared by the invention is great in area, is relatively uniform, is good inquality and is high in repetitive rate. The preparation method has the advantages of simple operation, short reaction time,low cost, and no pollution on environment.

The invention belongs to the analytical chemistry and photoinduced electrochemical sensor field and especially relates to a method for detecting dopamine by using a nanometer tungsten diselenide modified gold electrode photoinduced electrochemical sensor. Dichlorobenzene is used as a stripping agent to ultrasonically strip tungsten diselenide so as to obtain nanometer tungsten diselenide. An electrode is modified and the enhancement effect of the dopamine to a nanometer tungsten diselenide modified electrode photoinduced electrochemical signal is used to realize the testing of high sensitivityof the dopamine. The method is simple and cost is low.

The invention discloses an acceleration sensor based on a suspension two-dimensional material and a heterogeneous layer suspension mass block, and the acceleration sensor is characterized in that thesuspension two-dimensional material and the heterogeneous layer suspension mass block are used as a spring-mass block system and a transconductance device structure; materials used by the suspension two-dimensional material and the heterogeneous layer mainly comprise graphene, hexagonal boron nitride, molybdenum disulfide, tungsten diselenide, molybdenum diselenide, tungsten disulfide, platinum diselenide and other transition metal disulfide compounds. The external applied acceleration (such as along the Z-axis direction) deforms and strains the suspended two-dimensional material and the heterogeneous layer of the suspended mass (such as along the Z-axis), so that the resistances of the piezoresistive suspended two-dimensional material and the heterogeneous layer are changed, and the applied acceleration can be detected. The sensitivity, the resolution, the detection limit and the yield of the acceleration sensor are greatly improved by using a large suspended mass block, a two-dimensional material with a high piezoresistance coefficient and a heterogeneous layer and using the hexagonal boron nitride as a packaging layer, and the degradation of the performance of the acceleration sensor is avoided.

The invention discloses a self-excitation storable photoconductive device and a preparation method thereof. According to the invention, a single crystal STO substrate is used as an insulating oxide, and after ion beam bombardment, a nano conductive thin layer, namely surface electron gas SSEG, is formed on the surface layer of the single crystal STO substrate, and an N-type semiconductor is formed; WSe2 is a P-type two-dimensional semiconductor material, layers are combined together through Van der Waals force to form tungsten diselenide and strontium titanate surface electron gas and PN junctions thereof; the structure is simple, the photoelectric efficiency is high, storage property can be achieved, storage of photo-generated electron hole pairs can be achieved, and photo-generated carriers with the infinite service life are obtained; the working process is self-excited, the external quantum efficiency is high, the structure is simple, and the device can be applied to the field of nano energy devices.

The invention discloses a diselenide / layered double hydroxide composite water electrolysis catalytic material which is a material with diselenide growing on the surface of layered double hydroxide in-situ. Diselenide is molybdenum diselenide and / or tungsten diselenide. The invention also provides an in-situ anion intercalation and in-situ self-assembly preparation method of the diselenide / layereddouble hydroxide composite water electrolysis catalytic material under ultrasonic enhancement. The invention also discloses an application of the diselenide / layered double hydroxide composite water electrolysis catalytic material as an HER and / or OER material. The prepared diselenide / layered double hydroxide composite water electrolysis catalytic material not only has a low hydrogen evolution over-potential, but also has oxygen evolution reaction (OER) over-potential basically equivalent to that of noble metal, and is very excellent in performance. Therefore, the catalytic material is of greatsignificance to the improvement of the water electrolysis hydrogen production level.

The invention discloses a novel preparation method of a WSe2 (tungsten diselenide) nanowire thin film material and application in photocatalytic reduction of CO2 (carbon dioxide), and belongs to the technical field of preparation of materials and high-value utilization of CO2. The WSe2 nanowire thin film material is prepared by the following steps of using tungsten sheets and selenium powder as precursors; properly treating the precursors; then using a tubular furnace as a reactor, and calcining in the filled hydrogen gas / inert gas mixed gas, so as to obtain the WSe2 nanowire thin film material. The obtained sample has an excellent property in photocatalytic reduction of CO2. The prepared WSe2 nanowire thin film material has the advantages that the thickness is controllable, the surface isflat and smooth, the specific surface area of the catalyst material is large and the like; meanwhile, in the whole process, the cost is low, the efficiency is high, the green and environment-friendlyeffects are realized, the stability of the catalyst is high, the actual production requirement is met, and the larger application potential is realized.

The invention provides a two-dimension material heterojunction sensor, and belongs to the technical field of MEMS. The sensor structurally comprises a selective layer, a tungsten diselenide layer, a molybdenum disulfide layer and a substrate from top to bottom in sequence, wherein the tungsten diselenide layer and the molybdenum disulfide layer are overlapped to form a heterojunction; the surfaceof the heterojunction is modified with an anti-body corresponding to a to-be-tested tumor marker, the sites, which are not covered with the anti-body, on the surface of the heterojunction are filled with bovine serum albumin, and the anti-body and the bovine serum albumin form the selective layer. Metal electrodes are connected with the molybdenum disulfide layer and the tungsten diselenide layerrespectively, the heterojunction formed by tungsten diselenide and molybdenum disulfide is used as the core sensitive part of the sensor, the concentration of the marker is detected by using the characteristic that the heterojunction is sensitive to protein molecules, and the sensor has an important significance for early diagnosis of cancer.

Disclosed is a miniature piezoresistive type stress sensor based on tungsten diselenide. The miniature piezoresistive type stress sensor comprises a boron nitride layer, a metal electrode, a tungstendiselenide layer and a flexible substrate which are arranged in sequence from the top to bottom; the two ends of the tungsten diselenide layer are connected with the metal electrode; the upper surfaceof the tungsten diselenide layer is completely covered with the boron nitride layer; and the tungsten diselenide layer is a two-dimensional material, namely only single-layer atoms or a few layers ofatoms are arranged in the thickness direction, wherein the number of a few layers is 1-10. According to the miniature piezoresistive type stress sensor, tungsten diselenide is used as a core sensitive material, and stress detection is performed based on the characteristic (the piezoresistive property) that tungsten diselenide is sensitive to stress; and boron nitride is used as a protection layer, so that the stress sensor has the characteristics of high bending resistance, relatively high measuring range, high sensitivity, small size, easy processing, high long-term stability and the like.