75 results about "Polyactive" patented technology

The invention discloses a doped perovskite catalyst with a noble metal exposed on the surface, a preparation method and application thereof, belongs to the technical field of catalytic materials, and particularly relates to application in catalytic removal of volatile organic compounds. The method comprises the following steps: performing composite molding on rare earth elements / alkaline earth metals, transition metals and noble metals by adopting a sol-gel method, and performing strong acid surface etching and other operations. The surface of the catalyst is provided with a noble metal nanocluster or noble metal nanoparticle structure, so that the surface area is increased, more active sites can be provided, the adsorption of reactant molecules is enhanced, and the conversion rate and selectivity of a catalytic reaction are further improved. Based on the structure and performance advantages, the catalyst disclosed by the invention can be used for efficiently removing volatile organic compounds, can effectively reduce the initial temperature of the catalytic oxidation reaction of the volatile organic compounds, and has a wide application prospect in treating various industrial processes needing high-temperature and efficient catalysis.

The invention discloses a preparation method of a bifunctional heterojunction catalyst for AEM electrolyzed water. The method comprises the following steps: step 1, mixing multi-walled carbon nanotubes, deionized water, absolute ethyl alcohol and inorganic acid; step 2, putting the mixed solution in the step 1 into an ultrasonic machine to form a porous structure and more active adsorption sites; step 3, carrying out freeze drying treatment on the mixed solution treated in the step 2; step 4, mixing the dried multi-walled carbon nanotubes with acetylacetone salt, and uniformly grinding the mixed powder; and step 5, putting the powder obtained in the step 4 into a tubular furnace, and carrying out heat treatment in the atmosphere of H2 / Ar to obtain the PtFeCoNiMoZr / ZrO heterojunction catalyst. The catalyst has a remarkable catalytic effect on HER and OER reactions, and meanwhile, stable electrolysis which stably runs for 200 hours in an AEM electrolytic cell under the current density of 1200 mA / cm < 2 > is successfully realized.

The invention belongs to the technical field of electrocatalytic nitrate reduction catalysts, and particularly relates to a graded porous hollow carbon fiber catalyst with synergistic monatomic iron and ferric oxide clusters as well as a preparation method and application of the graded porous hollow carbon fiber catalyst. The preparation method specifically comprises the following steps: stirring polyacrylonitrile and polymethyl methacrylate in an organic solvent to obtain a spinning precursor solution; the preparation method comprises the following steps: taking ferrous sulfate heptahydrate and 1, 10-phenanthroline as ligands, and stirring in an organic solvent to obtain a metal organic ligand; the preparation method comprises the following steps: stirring a spinning precursor solution and a metal organic ligand, obtaining a metal precursor-loaded composite fiber through an electrostatic spinning technology, and then carrying out pre-oxidation and high-temperature pyrolysis to obtain the composite fiber. The prepared carbon fiber has good conductivity and a unique hollow hierarchical porous structure, transmission of reactants is greatly promoted while more active sites are exposed, the carbon fiber serves as a monatomic synergistic cluster catalyst carrier, rapid transmission of electrons is facilitated, and the electro-catalysis efficiency is effectively improved.

The invention relates to the technical field of oxygen reduction catalysts, in particular to a Fe-Sn diatomic site catalyst and a preparation method thereof.The Fe-Sn diatomic site catalyst comprises a nitrogen-containing carbon matrix, Fe atoms and Sn atoms, the Fe atoms and the Sn atoms are loaded on the nitrogen-containing carbon matrix, and the nitrogen-containing carbon matrix is formed by polymerizing and carbonizing dopamine hydrochloride. The Fe-Sn double-atom site catalyst provided by the invention prevents metal atom agglomeration, has more active sites, and shows excellent catalytic activity and stability in ORR reaction.

This invention belongs to the field of SERS detection technology and relates to the application of an Ag / Bi4O5Br2 / Ni-Fe double hydroxide composite SERS substrate in the detection of CV in wastewater. First, a Bi4O5Br2 / Ni-Fe double hydroxide is prepared, and silver nanoparticles are loaded onto its surface using a liquid-phase chemical reduction method. This material combines the LSPR effect of silver nanoparticles with the interfacial coupling and multiple active sites of the Ni-Fe double hydroxide, enabling the regulation of interfacial charge transfer and enhancing molecular adsorption. Utilizing the excellent adsorption and enrichment properties of Bi4O5Br2, a highly efficient charge transport system is synergistically constructed from multiple components, improving the SERS chemical enhancement effect and amplifying the CV Raman signal. This invention overcomes the shortcomings of weak signals and insufficient stability of single substrates, achieving sensitive detection of trace CV in water. The substrate preparation process is simple, environmentally friendly, and highly practical, showing broad application prospects in the field of trace CV analysis in aquatic environments.

The invention discloses a preparation method of curcumin, and belongs to the technical field of natural product extraction. The method comprises the following steps: firstly, adopting a modified deep-eutectic solvent into which propyl gallate is introduced as an extraction medium, and realizing high-selectivity extraction of curcumin through a special molecular structure of the modified deep-eutectic solvent; then the ultrasonic-microwave coupling technology is combined, so that the extraction efficiency is remarkably improved; finally, the modified molecularly imprinted polymer with magnetism is used for precise purification, the material has the specific recognition capacity and the rapid magnetic separation characteristic, polyethylene glycol is introduced to serve as a pore-foaming agent, and more active sites are provided for adsorption of curcumin molecules. According to the method disclosed by the invention, through collaborative innovation of all links, the whole process optimization from extraction to purification is realized, the product purity and the extraction efficiency are remarkably improved, the energy consumption and the solvent pollution are greatly reduced, and a reliable solution is provided for industrial production of the high-quality curcumin.

This invention discloses a composite nanodelivery system encapsulated in a fusion membrane, its preparation method, and its applications. The nanodelivery system comprises a Ti3C2 / TiO2 / CuInS2 composite material, oxaliplatin loaded thereon, and a fusion membrane encapsulating the outer layer; the fusion membrane is formed by the fusion of Fusobacterium nucleatum extravesicles and M1 macrophage membranes. This invention also discloses a method for preparing the nanodelivery system, including the steps of preparing the Ti3C2 / TiO2 / CuInS2 composite material, preparing the fusion membrane, loading oxaliplatin, and encapsulating it in the fusion membrane. The nanodelivery system prepared by this invention exhibits pH-responsive drug release characteristics, generating H2S in the tumor microenvironment and H2 under light irradiation, while also possessing photocatalytic activity. This invention combines chemotherapy, photoelectrocatalytic therapy, and the regulation of multiple active substances, and can be used to prepare drugs for treating malignant tumors of the digestive system.

The present disclosure belongs to the technical field of lithium-sulfur batteries, and discloses covalent triazine framework polymer nanosheets for cathode materials in lithium-sulfur batteries. The hexaazatriphenylenehexacarbonitrile monomer on the surface of sodium chloride is polymerized through high temperature triazine, sodium chloride crystal is removed to obtain covalent triazine framework polymer nanosheets product, and cathode materials in lithium-sulfur batteries are obtained after melting sulfur. The preparation method of the present disclosure is simple, has low cost, high yield, and uniform structure. The obtained material itself has a porous structure and numerous active sites. When used in lithium-sulfur batteries, it can promote the rapid conversion of lithium polysulfides, effectively suppress the shuttle effect, and improve the rate performance and cycle performance of lithium-sulfur batteries.

The application discloses a kind of composite skin care active raw materials and preparation method thereof, belong to cosmetic raw material technical field.The composite skin care active raw material includes by mass percentage: anti-sugar active component 1.0%-10.0%, firming and lifting active component 0.5%-8.0%, antioxidant active component 1.0%-4.0%, penetration promoting component 0.5%-2.0%, and the balance is cosmetic grade solvent.The application realizes the four synergistic effects of anti-sugar, firming, antioxidant and penetration promotion by compounding multiple active components at a specific ratio, the system is stable, not delaminated, not discolored, skin feels fresh, the preparation process is mild and simple, easy to industrial production, and can be widely used in essence, emulsion, cream, mask and other skin care products.

The invention relates to the technical field of catalysts, in particular to a nitrogen-carbon anchored hollow structure catalyst as well as a preparation method and application thereof. The nitrogen and carbon anchored hollow structure catalyst comprises a MoS2 carrier and active metal M particle doped nitrogen and carbon loaded on the MoS2 carrier, and is represented by M (at) NC / MoS2, and M is selected from one of Ni and Pt; the mass of the active metal M particles accounts for 5-15% of the mass of the MoS2 carrier. By constructing a nitrogen-carbon anchoring hollow structure, active metal M particles are uniformly doped in the nitrogen-carbon structure and are loaded on the MoS2 carrier, so that a synergistic effect of multiple active sites is realized, and the activity and the stability of the catalyst in a water gas shift reaction are improved.

The invention belongs to the field of synthesis of electrode materials, and particularly relates to a one-dimensional chain polymer with multiple active sites as well as a preparation method and application of the one-dimensional chain polymer. The polymer is prepared by carrying out dehydration condensation reaction on 1, 8, 4, 5-naphthalene tetracarboxylic anhydride and 2-nitro-1, 4-phenylenediamine in an inert atmosphere, and after the reaction is finished, washing with deionized water and carrying out suction filtration to obtain a target product. The molecular structure of the material simultaneously contains multiple oxidation-reduction active centers such as carbonyl and nitryl, so that efficient Zn / collaborative storage can be realized. When being used as a positive electrode of a zinc ion battery, the composite material shows high discharge capacity and long cycle stability, and an assembled flexible battery also has high volume energy density, excellent repeated bending resistance and chemical self-charging capacity in air, and has wide application potential in the field of wearable electronic equipment. The synthesis process is simple, raw materials are easy to obtain, reproducibility is good, and the method is suitable for large-scale production.

The preparation method of the antimony trioxide with the porous structure comprises the following steps: adding an antimony trioxide matrix into a montmorillonite loading agent which is 5-8 times of the total amount of the antimony trioxide matrix, stirring, carrying out suction filtration, and drying to obtain the antimony trioxide with the porous structure. An antimony trioxide matrix is constructed by adopting a double emulsion template method, meanwhile, montmorillonite is pretreated, interlayer water is damaged by preheating at 210-230 DEG C, then the temperature is increased to 350 DEG C, heat preservation is performed for 1 h, an interlayer structure is stripped through thermal expansion, the specific surface area is increased, more active sites are exposed, and the specific surface area is increased. And dopamine / carbon nanotube composite modification: dopamine hydrochloride is subjected to self-polymerization under a weakly alkaline condition to form a polydopamine (PDA) coating layer.

The invention discloses a method for preparing HFO-1234yf by dehydrofluorination of HFC-245eb, which comprises the following steps: under the action of a catalyst, dehydrofluorination of HFC-245eb is carried out to obtain HFO-1234yf; the catalyst comprises an aluminum fluoride coated SBA-15 carrier and multi-metal active components A and B loaded on the carrier, A is Cr, and B is one or more than two of Mg, Fe, Ni, Co and Zn. According to the invention, high dispersity of active sites and rapid mass transfer of reactants / products are ensured by utilizing high specific surface area and uniform pore channels of SBA-15. The multi-metal nanoparticles provided by the invention have higher thermal stability. The strong interaction among various metals can improve the Tanchmann temperature of the nano particles, so that the nano particles can better maintain fine sizes at the reaction temperature, and more active sites are exposed.

The application discloses iron-doped biochar loaded CuS, a preparation method thereof and application of the iron-doped biochar loaded CuS in removal of orange G by activated peroxodisulfate. The iron-doped biochar loaded CuS comprises porous biochar, and Fe2O3 particles, CuS and FeS loaded on the surface and in the pores of the porous biochar. In the application, transition metals are used to improve the surface properties of BC, introduce new active sites, obtain modified biochar, and then load CuS on the surface of the modified biochar, so that the PS catalyst with multiple active sites can be obtained, and the problems of low catalytic performance of original BC and agglomeration and deactivation of CuS can be solved.

The invention relates to a preparation method and application of bowl-shaped polyaniline microspheres, and polyaniline microspheres with regular bowl-shaped morphology are synthesized by accurately controlling key parameters such as the oxidation degree of aniline monomers, the template size, the dosage of a polymerization initiator and the like. The bowl-shaped polyaniline microspheres are formed by self-assembly of polyaniline molecules, and the interior of each bowl-shaped polyaniline microsphere is provided with a continuous and uniformly-distributed nano-scale pore structure. Due to the unique bowl opening and bowl bottom sizes in the bowl-shaped microsphere structure, the microsphere has the characteristics of concave cavity, micron hollow hemisphere shape, nanoscale bowl wall thickness, high surface area-volume ratio and high porosity at the same time, more active sites can be provided, and the bowl-shaped microsphere structure can be used for supercapacitor electrodes, gas sensor electrodes and electromagnetic shielding materials.

This invention discloses a method for synthesizing a bifunctional PdCu catalyst for electrocatalytic hydrogenation-coupled oxidation of HMF. The method involves chemically oxidizing a copper foam framework to induce in-situ growth of nanowire structures on the surface of the copper foam nanowire substrate. A palladium salt is used as the palladium source and loaded onto the copper foam nanowire substrate in a cluster form. The prepared catalyst possesses a nanowire structure that facilitates the loading of Pd clusters, generating more active sites. The Pd clusters provide active hydrogen (H*) to accelerate electron transport, thereby achieving efficient hydrogenation of high-concentration HMF to BHMF at the cathode. Simultaneously, when applied to the anode, it enables efficient HMF conversion to FDCA. This material is suitable for the continuous production of high-value-added products FDCA and BHMF through electrocatalytic hydrogenation-coupled oxidation. The catalyst exhibits high activity, high stability, and high electron utilization, demonstrating significant potential for industrial application.

The invention belongs to the technical field of heterogeneous catalysts for synthesis of polycaprolactone-polyethylene glycol segmented copolymers, and particularly relates to a copper-silicon-tungsten-containing heteropoly acid metal MOF heterogeneous catalyst and a preparation method thereof. The polyacid type metal-organic framework heterogeneous catalyst can effectively catalyze epsilon-caprolactone and PEG to carry out ring-opening copolymerization so as to prepare a related technology of the PCL-PEG segmented copolymer, and the related technology is not reported yet. Aiming at the problems, the invention provides the copper-silicon-tungsten-containing heteropolyacid metal MOF heterogeneous catalyst, the chemical formula of the copper-silicon-tungsten-containing heteropolyacid metal MOF heterogeneous catalyst is [Cu2 (L) 3 (SiW12O40) (H2O) 4] n, and the catalyst is a heterogeneous catalyst, not only inherits the characteristics of high specific surface area and adjustable structure of an MOF material, but also has excellent catalytic activity and acidity of heteropolyacid, provides more active sites for catalytic reaction, and has a good application prospect. Compared with a traditional homogeneous catalyst, the catalyst has the advantage that the catalyst can be easily separated from and recycled from a reaction system.

The invention discloses intrinsic flame-retardant polyurea resin as well as a preparation method and application thereof, and belongs to the technical field of flame-retardant polyurea protective coatings. The intrinsic flame-retardant polyurea resin comprises a component A and a component B. The component A comprises a prepolymer prepared from reactive phosphorus-containing resin and isocyanate, a liquid phosphate flame retardant and amino polyether, and the component B comprises amino polyether, an intumescent halogen-free flame retardant, an amino chain extender, a coupling agent and a catalyst. The phosphorus-containing resin with polyfunctional groups is introduced, participates in the polymerization reaction of the polyurea material, and is synergistically combined with the liquid flame retardant and the intumescent halogen-free flame retardant, so that the flame-retardant effect of the polyurea material is effectively improved, and meanwhile, the flame-retardant performance of the polyurea material is improved. A net structure formed by multiple active groups and an intumescent carbon layer structure formed in the intumescent flame retardant form a synergistic effect, so that the problem that a polyurea material is easy to drip is solved, and the intrinsic flame-retardant polyurea resin with obviously improved flame retardance and capability of ensuring the mechanical properties of the original polyurea material is obtained.

The application discloses an electro-enhanced activation persulfate oxidation method for removing organic pollutants with low consumption through cooperation of anode and cathode, uses LaCoO3 modified Ti4O7 active electrochemical film rich in oxygen vacancy as an anode, and uses in-situ grown nano-carbon modified carbon felt as a cathode to construct an anode-cathode cooperative activation persulfate system, achieves 100% removal of sulfamethoxazole within 37.3 seconds, and the energy consumption is only 0.0015 kWh / m 3 ·order. The technology meets the demand of high flux (1061 L / m 2 ·h) for complete degradation of pollutants, and can also realize deep mineralization (89%) of pollutants at slightly lower flux (212.22 L / m 2 ·h). Compared with the prior art, the bipolar activation persulfate system of the application has the characteristics of significantly improving the space-time efficiency by using bipolar multi-active sites, solving the problems of low wastewater treatment capacity, poor mineralization and high energy consumption of the single-pole system, and efficiently treating actual marine aquaculture wastewater and domestic sewage. The application has excellent pollutant removal and mineralization efficiency, wide pH application range, good stability, long service life, and wide application prospect.

The invention relates to the field of new food packaging materials, and discloses viscous-dominated thermoplastic starch as well as a preparation method and application thereof.The viscous-dominated thermoplastic starch is prepared by preparing hydrated starch particles in advance, preliminarily destroying a starch crystal region structure, promoting disordering of a starch chain, providing more active sites for subsequent acidolysis and introducing a structure regulator in a secondary extrusion process, so that the viscous-dominated thermoplastic starch is prepared. And cooperative regulation and control on the molecular structure and rheological behavior of the starch are realized. The resulting viscosity-dominant thermoplastic starch exhibits viscosity-dominant rheological properties in the molten state, the loss modulus (G '') of which is entirely higher than the storage modulus (G ') in the test frequency range. Based on the characteristics, when the viscous dominant type thermoplastic starch and the biodegradable polyester are blended, excellent processing matching performance and interface compatibility are shown, phase separation can be inhibited, the film forming stability can be improved, and therefore the mechanical property of the composite film is improved. The method is simple in process and low in cost, and has a good industrial application prospect.

The application discloses a zeolite molecular sieve-based catalyst and a preparation method and application thereof. The zeolite molecular sieve-based catalyst has low harmful element leaching, multiple active sites and high performance, and has excellent catalytic degradation performance and environment-friendly characteristics in environmental purification applications.

The application provides a polyurethane modified asphalt material containing a dynamic covalent bond structure, which comprises 70-90 parts of base asphalt, 8-29 parts of isocyanate prepolymer, 0.5-5.0 parts of a dynamic crosslinking agent, 0.3-1.5 parts of a common crosslinking agent and 0.01-0.1 parts of a catalyst; the dynamic crosslinking agent is a double / multi-active end group compound containing a dynamic bond or a multi-functional compound which can react with an isocyanate group to form a dynamic bond group. The application further provides a preparation method of the polyurethane modified asphalt material containing the dynamic covalent bond structure. In conclusion, the polyurethane modified asphalt material containing the dynamic covalent bond structure has excellent low-temperature performance, fatigue resistance, active healing ability and good regeneration performance.

In one aspect, compositions or formulations for unwanted plant control are described herein. In some embodiments, a composition described herein comprises an active ingredient component, a surfactant component, and a solvent component. In some embodiments, a composition comprises Fenoxaprop-p-ethyl, and at least one of Carfentrazone-ethyl and / or Triclopyr-butoxyethyl ester.

The invention relates to the technical field of batteries, in particular to a tab based on a micro-riveting structure and a preparation method and application thereof.The tab comprises a connecting piece and tab glue, the connecting piece and foil are of an integrated structure, and a micron-sized micropore array is arranged on the connecting piece; the maximum span L of micropores in the micropore array is 0.1-0.8 mm, the transverse center distance A1 is 0.5-1.5 mm, and the longitudinal center distance B1 is 0.5-1.5 mm. The tab glue comprises two tab film bodies, and the two tab film bodies cover the two sides of the thickness direction of the connecting piece respectively and are connected through the micropore array after hot pressing. When the tab is used for a soft package battery, a'colloid rivet 'penetrating through multiple layers of tabs is formed between the tab layers, so that three-dimensional mechanical interlocking is realized, under the requirement of the same stripping force, the width of a tab film is remarkably reduced, and a top sealing area is folded during combined packaging, so that the space of a battery cell is favorably saved for accommodating more active substances, and the service life of the battery cell is prolonged. And the purpose of improving the battery energy density is achieved.

The invention discloses a phenylboronic acid functionalized polyionic liquid catalyst which is synthesized in one step through hydrothermal free radical copolymerization by taking phenylboronic acid imidazolium salt ionic liquid (PBIL) as a monomer and divinyl benzene (DVB) as a cross-linking agent. The catalyst efficiently catalyzes the cycloaddition reaction of CO and epoxide under the conditions of no solvent, normal pressure and 90-100 DEG C through the synergistic effect of multiple active sites of hydroxyl, imidazolyl and Br, and the conversion rate of 1, 2-epoxyhexane reaches 99%. The catalyst can be recycled and is stable in structure, the problem that high pressure / co-catalyst is needed in the prior art is solved, and the catalyst has industrial application potential.

The invention relates to the technical field of natural product separation engineering, discloses a method for synchronously separating and purifying multiple active components of camellia oleifera shells based on synergistic extraction-gradient desorption-targeted refining, and aims to solve the technical bottleneck that high-purity tannin, proanthocyanidin and tea saponin cannot be efficiently and synchronously obtained from the camellia oleifera shells in the prior art. The core innovation is as follows: 1) an ultrasonic-microwave synergistic extraction parameter matching system is designed, and efficient synergistic dissolution of three active components is realized through precise matching of ultrasonic power and microwave power (0.5-1.7): 1 in combination with a 65-75% ethanol aqueous solution; (2) a three-stage incremental ethanol concentration gradient elution strategy is innovatively adopted, and directed preliminary separation of component groups is realized through step-by-step elution of 20-30% ethanol, 50-60% ethanol and 80-95% ethanol according to polarity differences of the three components; and (3) establishing a targeted refining technology combination, adopting Sephadex LH-20 gel chromatography according to the molecular weight characteristics of proanthocyanidin, and adopting high-speed counter-current chromatography of an ethyl acetate-n-butyl alcohol-water system in a specific ratio according to the structural characteristics of tea saponin homologues to realize deep purification. The continuous synchronous preparation of three active components in the camellia oleifera shells is realized for the first time, the purity of tannin in the obtained product is greater than or equal to 75%, the purity of proanthocyanidin is greater than or equal to 90%, and the purity of tea saponin is greater than or equal to 92% (the proportion of oleanane saponin is greater than or equal to 85%), the utilization rate of raw materials is increased by 30% or above, and the solvent consumption is reduced by 25%. An efficient, economical and environment-friendly integrated technical scheme is provided for high-value utilization of the camellia oleifera shells, and the method has a remarkable industrial application value.

The present application relates to the technical field of electrochemical sensor, in particular to a kind of molecularly imprinted electrochemical sensor based on β-FeOOH nanoparticle and preparation method thereof.The preparation of the molecularly imprinted electrochemical sensor based on β-FeOOH nanoparticle includes the following steps: step one, preparation of modified electrode: β-FeOOH nanoparticles are grown in situ on carbon cloth using hydrothermal method;Step two, add RC and CBD;Step three, molecularly imprinted polymer (MIP) is polymerized using cyclic voltammetry, and the sensor MIP / β-FeOOH / CC is prepared.The electrode selected in the present application is carbon cloth electrode, which can provide more active sites for molecular imprinting;It is easy to obtain and low in price, and at the same time, it does not need to be polished, which simplifies the preparation process;When preparing, simple one-step hydrothermal method is used, and in repeatability and stability test, the relative standard deviation is less than 5%;The minimum detection limit is 0.025 nM, which can well meet the trace quantitative detection of carbendazim.

The application discloses a method for treating pulp and barking wastewater by using MOG-Fe / Al flocculants in a shape similar to coral stone, and comprises the following steps: preparing MOG-Fe / Al flocculants by using aluminum nitrate, iron nitrate and trimesic acid; diluting pulp and barking wastewater, adjusting pH and temperature, and adding flocculants and standing and settling. The MOG-Fe / Al flocculants are colloidal particles in a dense network shape, attached to more pores and similar to coral stone, have interwoven fibers or particles, are rich in mesoporous structures, can provide many active centers, are favorable for diffusion of molecules in the pores, have a large specific surface area of the material, further improve the adsorption performance in water treatment, and improve the removal rate. The results show that when the MOG-Fe / Al dosage is 1.0 g, the wastewater concentration is diluted to 100 times, the pH is 9, the flocculation temperature is 30 DEG C, the flocculation time is 12 h, and the wastewater turbidity removal rate can reach 98.3%.

The application discloses a preparation method of a pyrite carbon nitride composite material and application thereof. The natural pyrite after crushing and sieving is fully mixed with pyrolytic carbon nitride and is subjected to ball milling treatment to obtain the pyrite carbon nitride composite material. The ball-milled pyrite carbon nitride composite material is characterized by XRD and XPS, and it is proved that the natural pyrite is successfully compounded with the carbon nitride material. New bonds such as Fe-N and C-S-C are generated in the ball milling process, the electronic distribution and electronic path of the catalyst are changed, the interface electron transmission is enhanced, the composite material is uniformly distributed in the ball milling process, the specific surface area is increased, and more active sites can be exposed, so that a good catalytic degradation effect is achieved, 10 mg / L of sulfamethoxazole can be completely catalytically degraded within 5 min, the catalyst and the persulfate are used in small amounts, the preparation process of the catalyst is simple, and the catalyst has the characteristics of low cost and high efficiency.

The present application relates to a kind of gas phase method polyethylene metallocene catalyst to vanadium titanium system catalyst online switching method, preparation method includes the following steps: 1) catalyst unit pretreatment: to catalyst unit, add silica gel cleaning, then replace after purging with nitrogen, add vanadium titanium system catalyst standby;2) metallocene catalyst inactivation in reaction cycle system: stop metallocene catalyst injection reactor, inject catalyst deactivator into reactor and continue to circulate;3) reaction system purging replacement: pressure replacement is carried out with nitrogen;4) vanadium titanium system catalyst commissioning and initiation: inject passivator into reactor once, according to the target grade requirement of vanadium titanium system after switching, introduce comonomer, inject the above passivator second time, inject vanadium titanium system catalyst, complete online switching.Compared with prior art, the preparation method of the present application realizes the online switching of single active center catalyst to multi-active center catalyst, and does not introduce any impurities except deactivator.