251results about How to "Mild response" patented technology

The invention discloses a cellulose-based in-situ growth MOF composite aerogel preparation method, which comprises: mixing cellulose powder and dimethylimidazole, adding into deionized water, gradually adding cobalt nitrate and zinc chloride, uniformly stirring, carrying out a heating reaction, adding polyethyleneimine, uniformly stirring, adding a cross-linking agent, carrying out cross-linking, washing, and drying to obtain the cellulose-based in-situ growth MOF composite aerogel. The composite hydrogel is obtained; and finally, sealing, heating and baking the composite hydrogel, washing and drying to obtain the composite aerogel. According to the method, the MOF is synthesized on the cellulose in situ under the low-temperature water phase condition, the composite aerogel containing the MOF material is obtained, the MOF material synthesized on the cellulose in situ has good porosity and particle size and uniformly covers the cellulose, loss of active components is avoided, the problem that the MOF material is prone to agglomeration is solved, and the preparation method is suitable for industrial production. Meanwhile, the adsorption performance is also effectively improved, the adsorbent has good affinity with water, and the surface can be promoted to adsorb three metal ions of vanadium, molybdenum and nickel at the same time.

The invention provides an electrochemical biosensor based on a nanoparticle modified multilayer porous membrane and application of the electrochemical biosensor. The nano particle modified multilayer porous membrane is composed of a plurality of modified nano particles among membranes with nano pore channels. The electrochemical biosensor constructed based on the nanoparticle modified multilayer porous membrane has the following advantages: (1) good conductivity and stability; and (2) multiple capture probes are modified on the surfaces of the nano pore channels of the multi-layer porous membrane, so that multiple different targets can be respectively detected, and multiple different targets can also be detected at the same time. And (3) enzyme-free double-target sensitive normal-temperature amplification-free detection can be carried out. (4) preparation steps are simple, consumed time is short, and operability is high; and (5) the sensitivity and the specificity are high.

The invention belongs to the technical field of targeting exosome preparation, and particularly relates to a targeting modification method of a rose exosome, a hyaluronic acid modified rose exosome and application of the hyaluronic acid modified rose exosome. The method comprises the following steps: dissolving hyaluronic acid in a rose exosome, adding 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and N-hydroxysuccinimide, carrying out a reaction for 8-16 h, carrying out centrifugation, and carrying out resuspension precipitation so as to obtain a hyaluronic acid modified rose exosome; the volume mass ratio of the hyaluronic acid to the rose exosome solution is 1 mg: (0.5-1) ml, and the hyaluronic acid, the 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide and the N-hydroxysuccinimide are in an equal molar ratio. The characteristic that hyaluronic acid is highly compatible with an inflammatory cell CD44 receptor is utilized, the targeting property of the rose exosome to inflammatory cells is enhanced, and the utilization rate and the anti-inflammatory effect of the rose exosome are further improved.

The invention discloses a preparation method and application of composite nanoparticles with a gold-silver core-shell structure, and aims to solve the problems that silver halide precipitates are generated on the surface of a silver core and the silver core is etched in the prior art. The thiourea solution is used for replacing a halogen-containing reagent, uniform epitaxial growth of gold on the surface of the silver core is mildly achieved, the gold-shell silver-core nanoparticles which are evenly wrapped and stable in structure are prepared, and the gold-shell silver-core nanoparticles are suitable for the fields of immunodetection and the like and are good in color development effect and low in cost. The method comprises the steps of preparing a gold salt solution, preparing gold nano-seeds, preparing silver nano-cores and generating gold-shell silver-core nano-particles through a chemical reduction reaction, and the problem that a core-shell structure grows unevenly is solved. When the method is applied to immunodetection, the material cost can be remarkably reduced, and a better color development effect can be achieved.

The invention discloses a water-based acrylate composite adhesive emulsion, a water-based acrylate composite adhesive and a preparation method, and belongs to the technical field of acrylate composite adhesives. The waterborne acrylate composite adhesive emulsion is prepared from the following components in parts by weight: 450 to 520 parts of deionized water, 250 to 300 parts of a soft monomer, 119 to 215 parts of a hard monomer, 45 to 55 parts of polyurethane resin, 5.0 to 5.5 parts of a reactive emulsifier, 1 to 11 parts of a non-reactive emulsifier, 1.5 to 10.5 parts of a self-crosslinking monomer and 3.25 to 3.34 parts of an initiator. According to the invention, the non-reactive emulsifier and the reactive emulsifier are simultaneously used for emulsifying and modifying the polyurethane resin and the acrylate copolymer, so that the influence that the non-reactive emulsifier is easy to migrate to the surface of an adhesive film, so that the water resistance and the humidity and heat resistance of the composite adhesive become poor can be weakened; therefore, the moisture and heat resistance of the water-based acrylate composite adhesive can be improved.

The invention provides a synthetic method of 2-methyl-4-chloropropionic acid-polyethylene glycol ester, and belongs to the technical field of preparation of 2-methyl-4-chloropropionic acid-polyethylene glycol ester. The method comprises the following steps: adding o-cresol, dichloroethane and a catalyst, and reacting sulfuryl chloride at the temperature of below 15 DEG C; performing separation to obtain p-chloro-o-cresol and 6-chloro-o-cresol; adding p-chloro-o-cresol, 2-chloropropionic acid and caustic soda liquid to synthesize 2-methyl-4-chloropropionic acid; 2-methyl-4-chloropropionic acid is acidized, cooled, crystallized and sliced, 2-methyl-4-chloropropionic acid, polyethylene glycol and a neutral catalyst are added for a reaction, and the di-2-(4-chloro-2-methyl-phenoxy) propionic acid-polyethylene glycol ester is synthesized. The method is simple in process, mild in reaction and high in yield. By means of the synthesis method, a qualified product with the p-chloro-o-cresol content larger than 99% can be produced, other phenol impurities are not contained, the synthesis quality of p-chloro-o-cresol is guaranteed, meanwhile, synthesis of 2-methyl-4-chloropropionic acid-polyethylene glycol ester is easier to control, the product quality can be greatly improved, and meanwhile the domestic blank is filled up.

The invention is applied to the technical field of polishing pad preparation, and particularly discloses a preparation method of a high-density and high-hardness foamed polyurethane polishing pad, which comprises the following steps: S1, raw material pretreatment; s2, a prepolymer synthesis step; s3, a foaming and forming step; s4, demolding and post-processing are carried out; and S5, sheet detection and formula optimization: detecting the hardness and density of the treated polishing pad finished product, and correspondingly adjusting the mixing ratio of the raw materials according to the detection result. According to the preparation method of the high-density and high-hardness foamed polyurethane polishing pad, polyether polyol and polyester polyol are mixed and then react with isocyanate, the polyether polyol and the polyester polyol do not react, and the polyether polyol and the polyester polyol jointly participate in the reaction of the isocyanate after being mixed, so that the high-density and high-hardness foamed polyurethane polishing pad is prepared. The generated polymer combines the advantages of polyether polyol and polyester polyol, and has stronger mechanical properties and chemical resistance than a polymer generated from a single component, so that the quality of a finished product of the polishing pad can be improved.

The invention discloses a preparation method of magnesium acetyltaurine salt, which comprises the following steps: S1, dissolving taurine in water to react with strong base, and concentrating water to obtain corresponding taurine salt; s2, dispersing the taurine salt obtained in the step S1 in acetic acid to react with acetic anhydride, and concentrating the acetic acid to obtain corresponding acetyl taurine salt; and S3, dissolving the acetyl taurine salt obtained in the step S2 in water, adding magnesium salt, adjusting the pH value of a reaction system, adding a single post-treatment solvent, crystallizing, filtering, and drying to obtain the acetyl taurine magnesium salt. According to the preparation method of the magnesium acetyltaurate, provided by the invention, the dosage of acetic anhydride and a post-treatment solvent is effectively reduced, the generation of acid-containing wastewater can be remarkably reduced, the process is simple, the reaction is mild, the raw materials are cheap and easy to obtain, the yield is high, and large-scale industrial production is facilitated.

The invention discloses a preparation method of carbonyl fluoride, which comprises the following steps: with hexafluoropropylene and oxygen as raw materials, introducing gas into a reactor filled with a catalyst for reaction at high temperature; the catalyst is one of palladium oxide, ruthenium oxide, platinum oxide and molybdenum oxide. According to the scheme, the cost is low, the raw material utilization rate is high, and compared with other carbonyl fluoride synthesis methods, the reaction does not involve phosgene, fluorine and other dangerous chemicals, and reaction by-products are few. In addition, according to the method, the toxicity of raw materials is small, hexafluoropropylene can be completely reacted under the condition of excessive oxygen, the reaction process is environment-friendly and simple, and basically no three wastes are generated. According to the method, hexafluoropropylene and oxygen are adopted as raw materials which are common chemical raw materials and are cheap and easy to obtain, and the method is simple in reaction process, mild in reaction, easy to operate and suitable for industrial production.

The invention belongs to the technical field of preparation of isocyanate, and particularly discloses an isocyanate preparation method based on a rare earth upconversion material, which comprises the following steps: mixing and dissolving rare earth metal salt and ligand in absolute ethyl alcohol or anhydrous ethylene glycol, and performing solvothermal reaction to prepare rare earth nanoparticles; and calcining the prepared rare earth nanoparticles at 450-550 DEG C to obtain the rare earth up-conversion material. The preparation method comprises the following steps: adding the rare earth up-conversion material into a solution of an organic amine compound, and carrying out photocatalytic oxidation reaction under the irradiation of near-infrared light, so as to prepare the isocyanate, wherein the mass percent of the rare earth up-conversion material in the organic amine compound is 1-10%, and the mass percent of the rare earth up-conversion material in the organic amine compound is 1-10%. Through the light conversion characteristic of the rare earth upconversion material, the isocyanate reaction is smoothly carried out under the excitation of low-energy near-infrared light, and the method has the advantages of mild reaction, low equipment requirement, high efficiency and the like.

The invention relates to a polycarboxylate superplasticizer as well as a preparation method and application thereof. Comprising the following steps: mixing and dissolving IPEG and water, heating to a certain temperature, and adding an oxidizing agent to prepare a solution A; mixing a reducing agent and a chain transfer agent, and adding water to prepare a solution B; mixing an unsaturated acid monomer and a phosphate group-containing monomer, and adding water to prepare a solution C; and adding the solution B and the solution C into the solution A, stirring at a constant temperature until the reaction is completed, and cooling to room temperature to obtain the polycarboxylate superplasticizer, thereby completing the reaction. Compared with the prior art, the method has the advantages that the adsorption of the polycarboxylic acid water reducer to the micro powder is reduced, and the dispersion effect of the polycarboxylic acid water reducer is improved, so that the working performance of the high-micro-powder regenerated masonry mortar is improved, and the like.

The invention relates to the technical field of battery negative electrode materials, and particularly discloses an artificial SEI film coated negative electrode material as well as a preparation method and application thereof. The artificial SEI film coated negative electrode material comprises a negative electrode material matrix and an artificial SEI film coated on the surface of the negative electrode material matrix; a raw material of the artificial SEI membrane is an artificial SEI membrane glue solution, and a preparation method of the artificial SEI membrane glue solution comprises the following steps: introducing carbon dioxide and hydrogen fluoride into a hydroxymethyl cellulose lithium glue solution until the pH value of a system is 5.5-7.0 to obtain the artificial SEI membrane glue solution. According to the invention, CMC-Li is used as an organic lithium salt component of the artificial SEI membrane, a compact inorganic lithium salt component is introduced by introducing CO2 and HF, and the artificial SEI membrane is similar to a natural SEI membrane in component, so that the first effect and reversible capacity of the negative electrode material are remarkably improved, the rate rapid charge performance and cycle performance are improved, and the commercial value is relatively high.

The invention relates to the technical field of enzyme catalysis, relates to the technical field of bioengineering application, and in particular relates to a magnetic nitrilase catalyst for green cyclic synthesis of organic acid as well as a preparation method and application of the magnetic nitrilase catalyst. According to the method, nitrilase escherichia coli is fixed on a magnetic composite carrier in a covalent binding and adsorption-crosslinking manner to form a magnetic nitrilase catalyst, and the catalyst is used for catalytic synthesis of organic acid; after the reaction is finished, the magnetic nitrilase catalyst is recovered by magnetic attraction, and the reaction waste liquid is acidized to realize the purpose of green cyclic synthesis of the organic acid. The prepared magnetic nitrilase catalyst can stably exist in nitrile substances and has the advantages of being high in mechanical strength, low in enzyme activity loss rate and easy to store, the magnetic nitrilase catalyst and reaction liquid can be recycled, beneficial reference is provided for promoting clean, environment-friendly and efficient enzyme method production of organic acid, and the application prospect is wide. The method has huge application potential in continuous separation and industrial application.

The invention discloses a preparation method of octafluorocyclopentene, which comprises the following two steps of: firstly, reacting 4-cyclopentene-1, 3-diketone with a selective fluorine reagent in acetonitrile under the condition of reflux to generate a crude product second mixture, purifying the second mixture, and putting the purified second mixture into a second-step reaction to obtain the octafluorocyclopentene. Reacting with diethylamino sulfur trifluoride in dichloromethane to generate a third mixture; the method has the advantages of environment-friendly and simple reaction process, no generation of three wastes, low cost, easy obtaining, simple reaction process, mild reaction, no generation of waste gas pollution even if nitrogen protection is needed, easy operation, and suitableness for industrial production.

The invention provides a Cr2AlC-derived two-dimensional carbide material and a preparation method thereof, and the preparation method comprises the following steps: (1) preparing a Cr2AlC MAX phase: uniformly mixing three raw material powders of Cr powder, Al powder and C powder, then mixing with sodium chloride salt and potassium chloride salt, heating and sintering, cooling, washing, and carrying out vacuum drying to obtain a Cr2AlC MAX phase powder material; and (2) stripping of the Cr2AlC MAX phase: grinding and uniformly mixing the Cr2AlC MAX phase powder in the step (1), copper chloride salt, sodium chloride salt and potassium chloride salt, heating and preserving heat. And cooling to room temperature, centrifuging with deionized water, centrifugally washing with a FeCl3 solution, and freeze-drying to obtain the two-dimensional carbide material. The method is simple in step, mild in reaction, green and safe, complete and efficient stripping of Cr2AlC can be achieved, and the method can be used for two-dimensional stripping of other three-dimensional materials; the types of ions adsorbed on the surface of the two-dimensional material sheet layer are simple, F <-> harmful to electrochemical performance is not carried, and the obtained novel two-dimensional porous carbon material can be used as an electrode material in a supercapacitor.

The invention relates to a tetraarylmethane compound with indole and pyrrole frameworks and a synthesis method thereof. The chemical structural formula of the compound is shown as a formula 3. The synthesis method comprises the following steps: adding 2-indolyl carbinol and a pyrrole derivative as reaction raw materials into an organic solvent, stirring and reacting at room temperature under the catalysis of Bronsted acid or Lewis acid in the presence of an additive # imgabs0 # molecular sieve, tracking the reaction by TLC until the reaction is complete, filtering, concentrating and purifying to obtain the 2-indolyl carbinol derivative. According to the tetraarylmethane compound with indole and pyrrole frameworks synthesized by the invention, a biological activity test shows that the derivative has relatively high sensitivity and very strong cytotoxic activity on human liver cancer cells HepG2. According to the method, reaction conditions are relatively conventional, the reaction process is mild, simple and convenient, the cost is low, the method is suitable for industrial large-scale production, and the application range of the method is widened; various substrates are used as reactants, products with various structures are obtained, and the yield is high. # imgabs1 #

The invention discloses a preparation method for expanding the interlayer spacing of a two-dimensional lamellar material through self-generation of carbon dioxide by cooperation of phytic acid and urea. Hydrogen ions are ionized through phytic acid, urea is ionized, urea cations are generated, and therefore phytic acid and urea can smoothly enter the interlayer of the two-dimensional lamellar material. The phytic acid and the urea successfully react between layers of the two-dimensional lamellar material through heating to generate carbon dioxide, and the generated carbon dioxide can further enlarge the interlayer spacing of the two-dimensional lamellar material. In addition, the interlayer spacing of the two-dimensional lamellar material is enlarged, so that the two-dimensional lamellar material has a good mechanical enhancement effect and a good carbon dioxide fixing effect. When the exfoliated two-dimensional nanosheet material prepared by the method is applied to a polymer matrix, the flame retardant property and the mechanical property of the matrix can be improved.

The invention belongs to the technical field of organic synthesis, and provides a preparation method of diphenyl disulfide, which comprises the following steps: A, in a dry atmosphere filled with inert gas, mixing halogenated benzene and magnesium powder, reacting to generate a Grignard reagent, and cooling to 0-15 DEG C; and B, dissolving disulfur dichloride in a solvent, dropwise adding the solution into the Grignard reagent obtained in the step A, carrying out a stirring reaction at 0-15 DEG C, carrying out a quenching reaction by using a saturated ammonium chloride aqueous solution, and carrying out extraction, drying and concentration on an organic phase to obtain diphenyl disulfide. The method adopts a one-pot method for direct synthesis, and is green and environment-friendly, and high in yield and purity.

The invention discloses a lactobacillus delbrueckii subsp. Bulgaricus CCFM1520 for transforming curcumin to produce tetrahydrocurcumin to relieve nervous anxiety, and belongs to the technical field of microorganisms. The lactobacillus delbrueckii subsp. Bulgaricus CCFM1520 screened by the invention has the capability of converting curcumin, and can utilize curcumin and generate tetrahydrocurcumin. The invention further provides a synbiotic preparation prepared from the lactobacillus gasseri CCFM1481 and curcumin, the synbiotic preparation can be used as an anti-fatigue functional medicine, the individual behavioral memory level can be improved, the imbalance of body neurotransmitters (DA, 5-HT and NE) can be slowed down, the expression of body neuroprotection related genes (BDNF, TrkB, DRD1 and TH) can be improved, and the synbiotic preparation has a huge application prospect.

This invention discloses a wide-interlayer-spacing molybdenum disulfide catalyst, its preparation method, and its application, belonging to the field of water electrolysis for hydrogen production energy conversion technology. The preparation method includes the following steps: preparing a molybdenum disulfide precursor solution using a molybdenum source and a sulfur source; then subjecting the molybdenum disulfide precursor solution to a hydrothermal reaction with a carbon-containing interlayer-spacing regulator; and obtaining the wide-interlayer-spacing molybdenum disulfide catalyst after centrifugation and washing. The carbon-containing interlayer-spacing regulator is used to insert into the interlayer of molybdenum disulfide during the hydrothermal reaction, increasing the interlayer spacing of the (002) crystal planes of the obtained molybdenum disulfide catalyst. The wide-interlayer-spacing molybdenum disulfide catalyst of this invention facilitates electrolyte penetration and hydrogen bubble release, effectively avoids active site blockage, enhances the intrinsic conductivity of the catalyst, accelerates internal charge transport, increases active sites for hydrogen evolution reaction, and improves the intrinsic hydrogen evolution catalytic activity of the catalyst.

The invention provides a synthesis method of 1-amino-2-cyano-1-cyclopentene, which comprises the following steps: 1, mixing an ionic liquid and a super-strong organic alkali in a protective gas atmosphere, heating, stirring, uniformly mixing and dissolving to obtain a material A; the ionic liquid is selected from at least one of [BMIM] PF6, [BMIM] BF4, [BMIM] NTf2, [BMIM] OTf and [BMIM] OAc; 2, adiponitrile is dropwise added into the material A under stirring for a reaction, and a material B rich in 1-amino-2-cyano-1-cyclopentene is obtained; 3, cooling and crystallizing the material B, and carrying out pressure filtration to obtain an ACCP crude product; and 4, recrystallizing and refining the obtained ACCP crude product to obtain a pure product. The method provided by the invention has the advantages of simplicity, high efficiency, sustainable production, low cost, low content of generated three wastes, mild reaction conditions and suitability for industrial production.

The application discloses a preparation method of zolmitriptan, relates to the technical field of drug synthesis, and comprises the following steps: adding compound 1 and reagent 1 into solvent 1 to perform a first reaction to obtain compound 2; adding the compound 2, reagent 2 and reagent 3 into solvent 2 to perform a second reaction to obtain compound 3 and the like. Compared with the prior art, the application provides a novel synthetic route for preparing zolmitriptan, the route uses L-4-bromophenylalanine as a starting material, and new synthetic steps are adopted, such as using reagent 5, such as a t-butyl alcohol metal salt and sodium hydride, to construct the oxazolidinone structure in zolmitriptan and using a coupling reaction to construct the indole ring in zolmitriptan, so that the yield of the obtained target product is significantly improved, the use of high-toxicity and high-risk reagents in the existing synthetic route is effectively avoided, and a mild, efficient, green and environmentally-friendly synthetic route for preparing zolmitriptan is provided.

The invention discloses modified sodium alginate / quaternized chitosan self-expanding composite hemostatic powder and a preparation method thereof. The preparation method comprises the following steps: S1, preparing sodium alginate grafted dopamine through amidation reaction, dialyzing, freeze-drying and grinding into powder; s2, mixing the modified sodium alginate and the quaternized chitosan powder according to different mass ratios; s3, adding citric acid and sodium bicarbonate powder with different masses into the mixed powder, and uniformly mixing to obtain the modified sodium alginate / quaternized chitosan self-expansion composite hemostatic powder. The hemostatic powder obtained by the method has the excellent characteristics of blood-triggered expansion, fast gelation, shape self-adaption, coagulation promotion and the like, and has excellent hemostatic performance in deep irregular wounds. Compared with commercial styptic powder, the styptic powder prepared by the method is simple in preparation process, low in cost and relatively high in safety. The modified sodium alginate / quaternized chitosan self-expansion composite hemostatic powder has a great application prospect in the field of incompressible bleeding control materials.

The invention discloses a silver / graphene composite coating and a preparation method thereof, and belongs to the technical field of electrolysis or electrophoresis production process methods of coatings. The preparation method comprises the following steps: (1) pretreating the surface of the base material; (2) pre-silver plating and electroplating; (3) electroplating a pure silver layer; and (4) silver / graphene composite electroplating. The invention provides a mode of carrying out composite electroplating at an intermittent stirring speed, a thin silver layer is electroplated in a pre-silver plating solution, then a silver layer is plated in a pure silver plating solution, and finally electroplating is carried out in a silver / graphene composite plating solution, so that the composite plating containing the pre-silver plating layer, the pure silver layer and the silver / graphene layer is obtained. Therefore, the performance of the silver plating layer is enhanced, and the binding force of the plating layer and a base material is greatly improved. The method has the advantages of being convenient to operate, mild in reaction, low in cost and uniform in coating. The prepared silver / graphene composite coating has excellent conductivity, hardness, corrosion resistance and wear resistance, and has a good application prospect under outdoor working conditions.

The present invention discloses a biomass pyrolysis gas high-efficiency low-nitrogen burner, which belongs to the field of burners and includes an air duct and a gas pipe; wherein the gas pipe is sleeved inside the air duct, and the right end of the gas pipe penetrates the right end side wall of the air duct and extends to the outside; an air inlet pipe, wherein the air inlet pipe is installed on the upper surface of the air duct near the right end, and the inside of the air inlet pipe is interconnected with the inside of the air duct; an air intake pipe, wherein the air intake pipe is installed on the upper surface of the gas pipe near the right end, and the inside of the air intake pipe is interconnected with the inside of the gas pipe. Combustion can be achieved through multiple groups of nozzle pipes to form multiple groups of small flames for combustion. Compared with large flame combustion, when multiple groups of small flames are burned, the flame distribution is more dispersed, the combustion heat distribution is relatively uniform, and the situation of local high temperature is relatively rare. Such a design avoids the problem of high internal temperature of large flame combustion in the prior art and the generation of a large amount of nitrogen oxides as much as possible.

The present invention belongs to the field of catalytic technology, and specifically relates to a carbon nitride catalyst and a preparation method and application thereof, comprising the following steps: S1, mixing and grinding a precursor melamine and a modifier polyaspartic acid; S2, after the raw materials are mixed and ground, roasting them in an air atmosphere at a certain temperature to obtain a catalyst. The carbon nitride-based catalyst of the present invention can efficiently catalyze the conversion of glycerol to prepare glycerol carbonate without adding any solvent, and the maximum conversion rate of glycerol is as high as 97%, and the yield of glycerol carbonate is as high as more than 86%.

This invention belongs to the field of hollow multi-component nanomaterial preparation technology, specifically disclosing a hollow Cu3NbSe4 nanomaterial, its preparation method, and its application. The microstructure of the nanomaterial is a nanoscale hollow cubic structure. The preparation method includes: (1) dissolving niobium source and selenium source separately in oleylamine solvent by heating for later use; (2) treating the soluble copper source and the niobium source dissolved in (1) in a high-boiling-point organic solvent for deoxygenation and dehydration, and then carrying out a solvothermal reaction; (3) when (2) is heated to a certain temperature, injecting the selenium source dissolved in (1) to carry out a solvothermal reaction, and separating the obtained solid product after the reaction is completed. The synthesis process of this invention is simple, the reaction conditions are mild, and the energy consumption and cost are low; more importantly, it realizes the preparation of hollow Cu3NbSe4 nanomaterial with uniform morphology and size, high crystallinity, and stronger light absorption capacity, and the prepared hollow Cu3NbSe4 shows excellent performance in photocatalytic hydrogen production.

The invention provides a heterojunction nano composite material and a preparation method and application thereof, the heterojunction nano composite material comprises C3N4 / MoS2 / titanium dioxide nanotube heterojunction nano particles, and the C3N4 / MoS2 / titanium dioxide nanotube heterojunction nano particles are MoS2 / titanium dioxide mixed bodies of which the surface layers are coated with layered C3N4; wherein in the MoS2 / titanium dioxide mixed body, the titanium dioxide nanotubes grow in a highly oriented manner; the MoS2 nanosheets are in a petal sheet shape and are uniformly distributed on the surfaces of the titanium dioxide nanotubes. The material is stable in structure and high in organic pollutant removal efficiency; the preparation method is safe and simple, mild in reaction and low in toxicity, has the advantages of environmental friendliness, safety and controllability, is easy for large-scale production, and brings great innovation to future new energy development and environmental governance; the method is suitable for large-area popularization and application.

The present invention relates to the field of polyether polyols for polyurethane, and in particular to a method for preparing condensate-based rigid foam polyether polyols. The method comprises the following steps: adding cyclohexanone and paraformaldehyde into a reaction container, adding an alkali catalyst under continuous stirring, reacting to obtain a cyclohexanone formaldehyde condensate; adding cyclohexanone formaldehyde condensate and polyols as mixed initiators into the reaction container, adding a catalyst, heating and dripping the first section of alkylene oxide to extend the polyether chain, and continuing the internal pressure reaction after the feeding is completed to obtain an intermediate polyether polyol; heating and dripping the second section of alkylene oxide, pressurizing after the feeding is completed, and reacting the internal pressure to obtain a polyether polyol crude polymer; keeping the temperature and bubbling with nitrogen, discharging after bubbling, and obtaining a condensate-based rigid foam polyether polyol. Since the cyclohexanone formaldehyde condensate introduces a cyclic group, the introduction of the cyclic structure as an initiator in the process of synthesizing polyether reduces the deformation between molecular chains, thereby improving the demoulding property of the foam.

The invention belongs to the technical field of catalysis, and particularly relates to a carbon nitride catalyst and a preparation method and application thereof, and the preparation method comprises the following steps: S1, mixing and grinding a precursor melamine and a modifier polyaspartic acid; s2, mixing and grinding the raw materials, and roasting in an air atmosphere at a certain temperature to obtain the catalyst. The carbon nitride-based catalyst provided by the invention can efficiently catalyze glycerol conversion to prepare glycerol carbonate under the condition of not adding any solvent, the highest conversion rate of glycerol is up to 97%, and the yield of glycerol carbonate is up to 86% or above.