1383 results about "Oxygen vacancy" patented technology

The invention provides an in-situ modified lithium-rich manganese-based precursor and a preparation method and application thereof.The preparation method comprises the following steps that a nickel-cobalt-manganese mixed metal salt solution, a precipitator solution and a complexing agent solution are introduced into a base solution for a first coprecipitation reaction, and after the first coprecipitation reaction is finished, feeding is stopped; and introducing a doped nickel-cobalt-manganese mixed metal salt solution, a precipitant solution, a complexing agent solution and a carbon source solution into a system after the first coprecipitation reaction is finished, and carrying out a second coprecipitation reaction to obtain the in-situ modified lithium-rich manganese-based precursor. According to the preparation method, doping elements and a carbon source are introduced when the lithium-rich manganese-based precursor is prepared through the coprecipitation reaction, in-situ uniform construction of oxygen vacancies and a carbon coating layer on the surface of the material is synchronously achieved, the in-situ modified lithium-rich manganese-based precursor is obtained, the treatment step of subsequent secondary coating can be reduced, the production cost can be reduced, and the method is suitable for industrial production. The technological process is shortened.

According to the Pt cluster catalyst, the preparation method and the application, an aluminum oxide composite metal oxide carrier is prepared by adopting a pH swing method, a defect oxide nano island is formed through high-temperature reduction treatment, and oxygen vacancies contained on the surface can firmly anchor a subsequently loaded Pt cluster, so that the coking phenomenon of the Pt-based catalyst is reduced, and the catalytic activity of the Pt-based catalyst is improved. The catalytic activity and the stability of the Pt cluster catalyst are obviously improved. Meanwhile, Pt clusters are prepared through a heating reflux method, so that the Pt clusters have high dispersity and rich active sites, the finally prepared Pt cluster catalyst is small in Pt particle size and high in atom utilization rate, and when the Pt cluster catalyst is used for catalyzing a dehydrogenation reaction of a liquid organic hydrogen carrier, the Pt cluster catalyst is weak in adsorption capacity to a product, and the catalytic activity of the liquid organic hydrogen carrier is improved. The catalyst can show high conversion rate and hydrogen release rate at low temperature, can still keep stable structure at high temperature, and provides an efficient and reliable solution for engineering application of an LOHC dehydrogenation link.

The invention provides a composite material with an MOF structure as well as a preparation method and application thereof, the composite material comprises a main body material structure with oxygen vacancies coated with the MOF structure, the composite material is formed by in-situ growth of the MOF structure on a main body material with the oxygen vacancies, and the main body material with the oxygen vacancies is formed by in-situ growth of the MOF structure on the main body material with the oxygen vacancies. According to the MOF material, metal active sites capable of growing can be provided for the MOF structure, oxidizing gas generated by the battery under the extreme condition can be synergistically eliminated, the MOF material has Lewis acidity, the rate performance of the battery can be improved, reducing gas generated by the battery under the extreme condition can be adsorbed, and therefore the safety performance of the battery is improved.

The invention belongs to the technical field of monatomic nano-enzyme material preparation, and particularly relates to a nano-enzyme preparation method for acetylcholin esterase activity detection. The Ni-NiO heterojunction material is successfully synthesized by adopting Ni-MOF as a carrier and accurately regulating and controlling the ratio of nitrogen to air in the ultrafast Joule hot calcination process. The material has rich oxygen vacancies and metal Ni sites, the oxygen vacancies and the metal Ni sites can effectively serve as anchoring sites of Pt single atoms, the loading capacity and dispersity of the Pt single atoms are remarkably improved, and therefore the excellent nano-enzyme catalytic activity is shown. In addition, the preparation method disclosed by the invention is simple and convenient in process and has a wide industrial application prospect. An acetylcholin esterase activity colorimetric sensing method constructed on the basis of the nanometer enzyme for acetylcholin esterase activity detection prepared by the method has extremely high sensitivity and low detection limit. The detection limit of the technology can be as low as 0.037 mU / mL, the problem that the sensitivity of a traditional detection method in a low-concentration sample is insufficient is remarkably solved, and remarkable clinical application potential is shown.

The invention relates to a NiCoW-CoP / Co3O4 (at) NF self-supporting heterostructure catalyst and a preparation method thereof. The preparation method comprises the following steps: preparing a CoP-coated NF precursor on foamed nickel through a constant potential electrodeposition method, then carrying out annealing treatment in a muffle furnace, and finally carrying out electrodeposition on NiCoW-LDH to obtain the NiCoW-CoP / Co3O4-coated NF material. According to the preparation method, the microsphere material with the surface covered with the dendritic dendrites is synthesized, and exposure of active sites is increased through the special surface structure of the microsphere material. The compounding of the trimetal hydroxide containing high-valence tungsten and the introduction of oxygen vacancies can effectively enhance the local electron density of oxygen atoms on the surface of the catalyst, thereby enhancing the catalytic performance and seawater corrosion resistance of the material. Compared with the prior art, the method disclosed by the invention is simple to operate and low in cost, and the prepared catalyst has high electrocatalytic activity, relatively low hydrogen evolution overpotential and oxygen evolution overpotential and long-time stability. And the method has important theoretical significance and potential application value for developing a bifunctional electrocatalyst suitable for electrolyzing seawater.

The invention relates to the technical field of environmental functional materials and water treatment, and discloses a preparation method and application of a persulfate activator for efficiently removing drug-resistant bacteria and drug-resistant genes in water. Waste biomass and waste plastics are used as raw materials, solid waste resource utilization is achieved through synergistic pyrolysis, compared with a traditional catalyst, the preparation cost can be reduced by more than 40%, and remarkable economic and environmental benefits are achieved. The catalyst has the following advantages: 1) the limitation of a traditional single-active-site catalyst is broken through through the triple synergistic effect of transition metal oxide variable valence activation, nonmetal doped carbon electron conduction and an oxygen vacancy non-free radical path; 2) physical interception of ARB and enrichment of ARGs can be realized at the same time by utilizing a multi-stage pore channel structure; and (3) activating persulfate to generate free radicals (SO4 <->. / . OH) and non-free radicals (1O2 / electron transfer) to generate a double-path synergistic effect, thereby realizing efficient removal of ARB / ARGs in water.

The invention discloses a synthesis method of a hydrazine dicarboxylate modified cerium dioxide abrasive, and belongs to the technical field of precise polishing materials. The method comprises the following steps: taking cerous nitrate as a raw material, and preparing a cerous carbonate precursor through an ammonium carbonate precipitation reaction; and grinding and calcining the obtained precursor and hydrazine dicarboxylate to obtain the CeO2 grinding material with the surface rich in oxygen vacancies. And Ce < 4 + > can be partially reduced into Ce < 3 + > by reducing fragments generated by decomposition of the hydrazine dicarboxylate in the calcining process, so that an oxygen vacancy structure is formed through induction, and the chemical activity and the reaction rate of the abrasive are improved. The obtained grinding material shows excellent performance in chemical mechanical polishing (CMP) of K9 glass, the material removal rate (MRR) is increased by about 3.6 times compared with that of unmodified CeO2, the surface roughness (Ra) is reduced to about 0.16 nm or below, and grinding material particles are good in dispersity and less in agglomeration. The used hydrazine dicarboxylate is stable, low in toxicity and mild in reaction, and the particle size can be prevented from excessively growing while the high oxygen vacancy concentration is kept.

The invention relates to an iron oxide homogeneous and heterogeneous photoelectric self-Fenton electrode material as well as a preparation method and application thereof, the self-Fenton electrode material comprises a carbon fiber cloth matrix and an active alpha / beta-Fe2O3 homojunction grown on the carbon fiber cloth in situ, and the structure of the self-Fenton electrode material is shown as alpha / beta-Fe2O3 / CC. The alpha / beta-Fe2O3 homojunction is formed by compounding two phases, namely, alpha-Fe2O3 and beta-Fe2O3. And the alpha / beta-Fe2O3 / CC has an oxygen vacancy. The preparation method comprises the following steps: soaking a pretreated carbon fiber cloth substrate in an alpha / beta-Fe2O3 precursor solution prepared in advance for reaction, and after the reaction is finished, carrying out post-treatment to obtain FeOOH / CC; calcining the FeOOH / CC, and cooling to obtain alpha / beta-Fe2O3 / CC; the alpha / beta-Fe2O3 / CC can introduce oxygen vacancies through reduction activation treatment of a sodium borohydride aqueous solution. Compared with the prior art, H2O2 can be generated in situ, sustainable circulation from Fe < 3 + > to Fe < 2 + > is enhanced, generation of hydroxyl radicals in the self-Fenton reaction is promoted, and the degradation reaction speed and efficiency of organic pollutants, especially antibiotics are greatly improved.

The invention discloses an oxide thin film post-processing method based on multi-stage cooling annealing, and aims to actively regulate and control thin film stress while repairing oxygen vacancies through a precisely designed heat treatment process. According to the method, the problem that stress control and defect repair are difficult to consider in the annealing process is solved, and a solid theoretical basis and scientific basis are laid for preparing low-absorption and high-stability oxide intense laser thin film devices.

The invention relates to the technical field of chemical catalysts, in particular to a cerium-based solid solution loaded iron-based oxygen vacancy enhanced low-temperature ammonia synthesis catalyst. The heterovalent ions are doped in CeO2 crystal lattices to introduce strain and defects, so that the oxygen vacancy formation energy and concentration are greatly improved. Experiments show that the oxygen vacancy concentration (delta) of the Ce0. 8Zr0. 2O2-delta carrier disclosed by the invention can reach 0.12, which is 3-5 times that of pure CeO2. Under the conditions of 250 DEG C and 5 MPa, the ammonia synthesis rate reaches 120 [mu] mol / g / h, which is more than 20 times that of a traditional molten iron catalyst; under the conditions of 350 DEG C and 10 MPa, the ammonia synthesis rate exceeds 1000 [mu] mol / g / h and is close to the level of a noble metal ruthenium-based catalyst. As the working temperature is reduced by 100-150 DEG C, the reaction heat consumption is reduced by more than 30%, and the overall energy consumption is reduced by 25-40%.

The invention relates to a preparation technology of an electrochemical catalytic material, and aims to provide a method for preparing an electrode material through pulse electrodeposition and application of the electrode material in an oxygen evolution reaction. The method comprises the following steps: constructing a dual-electrode electrolysis system, and co-depositing transition metal ions and selenium ions on a working electrode by adopting a pulse electrodeposition method to form a catalyst layer containing transition metal and selenide; then the working electrode is used for building an electrochemical system, electrochemical activation treatment is conducted on the working electrode through cyclic voltammetry, a selenium phase is induced to fall off, porous metal oxide is formed by reconstructing the surface of a catalyst layer, and the electrode material for the water electrolysis oxygen evolution reaction is obtained. The selenium phase is induced to fall off through electrochemical activation to form a porous metal oxide structure, the specific surface area is remarkably increased, rich oxygen vacancies are formed, the electronic structure is optimized, more active sites are exposed, and the catalytic activity is improved; the method is easy to operate, high in parameter controllability, free of high-temperature and high-pressure equipment and suitable for large-scale production.

The invention provides a method for preparing a spinel type catalyst rich in oxygen vacancies under the assistance of magnetization treatment and application of the spinel type catalyst. The synthesis method of the catalyst comprises the following steps: (1) preparing a precursor of the catalyst by adopting a hydrothermal method: putting a metal foam carrier into a mixed solution of metal salt ions such as ferric nitrate, manganous nitrate and cobalt nitrate, adding ammonium fluoride and urea, carrying out hydrothermal reaction, repeating the hydrothermal reaction for several times, and washing and drying to obtain the precursor; and (2) putting the catalyst precursor into a magnetization reactor, putting the magnetization reactor in the center of an alternating magnetic field coil, and carrying out magnetization treatment on the catalyst precursor in an air or oxygen atmosphere to obtain the spinel type catalyst rich in oxygen vacancies. The method is simple in process and low in cost, and the obtained product is uniform in morphology and good in repeatability and has high photo-thermal catalytic oxidation toluene performance. Through a clean, pollution-free and in-situ directional heating electromagnetic induction auxiliary technology, removal of oxygen atoms on the surface of the spinel catalyst is promoted, so that rich oxygen vacancies are introduced into cobalt-manganese spinel, the exchange effect between the catalyst and oxygen molecules is accelerated, and the reaction rate of catalytic oxidation of VOCs is promoted. When the intensity of simulated sunlight is 500 cm <-2 >, the concentration of toluene is 1000 ppm, the air speed is 45000 mL.gcat <-1 >. H <-1 >, the conversion rate of toluene reaches 86% or above, and high-efficiency oxidation of toluene can be realized under the driving of the simulated sunlight.

The invention discloses a nitrogen-doped oxygen-vacancy-rich three-dimensional flower-shaped bismuth oxide electrocatalyst as well as a preparation method and application thereof, relates to the technical field of electrocatalysts, and solves the problems that a traditional bismuth oxide catalyst is insufficient in electron transfer capability and low in active site utilization rate. The preparation method comprises the following steps: dissolving bismuth nitrate, polyvinylpyrrolidone and sodium oleate in a mixed solvent of methanol and N, N-dimethylformamide, and stirring and dissolving to obtain a solution A; the preparation method comprises the following steps: dissolving 1, 3, 5-tri (4-carboxyl phenyl) benzene in a mixed solvent of methanol and N, N-dimethylformamide, and stirring and dissolving to obtain a solution B; and adding the B into the A, uniformly stirring, heating in an oil bath, reacting under magnetic stirring, cooling to room temperature, filtering, washing and drying the product to obtain white powder, calcining in a tubular furnace to obtain three-dimensional flower-shaped Bi2O3, putting in the tubular furnace, introducing argon, introducing ammonia gas, heating, and carrying out heat preservation reaction to obtain the electrocatalyst. The catalyst can be used for catalyzing nitrogen reduction synthesis ammonia reaction.

The invention belongs to the technical field of semiconductor material surface engineering and defect analysis, and provides an ultrahigh vacuum surface defect detection method and system based on a scanning tunneling microscope, and the method comprises the following steps: carrying out mechanical stripping on a bulk single crystal gallium oxide sample based on the cleavage property of a crystal, and obtaining a gallium oxide single crystal wafer with a micron thickness; placing the stripped single crystal gallium oxide sample in an ultrahigh vacuum environment, and removing atmospheric adsorbates on the surface through vacuum high-temperature annealing treatment; performing sputtering annealing cycle treatment on the surface of the preliminary annealing sample in an ultrahigh vacuum environment to generate an oxygen vacancy defect on the surface so as to obtain a post-treatment sample; the oxygen vacancy concentration, the surface cleanliness and the surface atom orderliness are verified through auxiliary characterization means (XPS, LEED); performing scanning imaging on the surface of the post-treatment sample through a scanning tunneling microscope (STM), and performing oxygen vacancy defect identification by combining with an oxygen vacancy defect STM image simulated by DFT calculation; according to the method, the atomic-scale resolution of the surface of the single crystal gallium oxide sample is detected through the scanning tunneling microscope, the oxygen vacancy defect and other various surface defects are accurately recognized, and the surface state of the sample is comprehensively evaluated.

The invention discloses a zirconium-based MOF material and a preparation method and application thereof, in the zirconium-based MOF material, metal ions are Zr < 4 + >, an organic ligand is ellagic acid, a conditioning agent is gallic acid, and the material has an oxygen vacancy structure and a hierarchical pore structure; the preparation method comprises the following steps: (1) mixing ellagic acid, gallic acid, zirconium oxychloride octahydrate and a solvent, and carrying out solvothermal reaction; and (2) washing and drying the solid after the reaction in the step (1) to obtain the zirconium-based MOF material. According to the invention, renewable and low-cost ellagic acid and gallic acid are respectively used as an organic ligand and a conditioning agent, and an oxygen vacancy structure is constructed in a competitive coordination manner, so that more hydroxyl and unsaturated metal Zr active sites are exposed, the interaction with formaldehyde (HCHO) is enhanced, and meanwhile, the oxygen vacancy structure can be used as an oxygen vacancy catalyst. And the existence of the hierarchical pore structure can effectively promote mass transfer, so that the HCHO adsorption capacity is improved.

The invention discloses a method for preparing a methanol fuel cell anode catalyst by doping a modified multi-walled carbon nanotube carrier. The method comprises the following steps: 1) acidizing an unmodified multi-walled carbon nanotube; (2) preparing the cerium oxide doped modified multi-walled carbon nanotube; and 3) preparing the cerium oxide doped modified multi-walled carbon nanotube carrier loaded PtFe bimetallic alloy catalyst. According to the method disclosed by the invention, the MWCNTs are induced by doping CeO2 to generate more oxygen vacancy defects, so that anchoring of more active sites of the PtFe alloy is facilitated, and MOR is promoted to improve the activity of the catalyst; the stable Ce < 4 + > can deform the surface structure of Pt, so that the binding bond energy of COads and-OH is stronger, and an anti-poisoning effect is achieved; the introduced Fe element and Pt have metal electronegativity difference, so that the adsorption bond energy of formic acid, formaldehyde and carbon monoxide intermediates generated by gradual dehydrogenation of Pt and methanol can be weakened, and the anti-toxicity effect is achieved; and the PtFe alloy and the CeO2 / MWCNTs are in synergistic interaction, so that the stability of the catalyst can be enhanced.

The invention provides an oxygen vacancy defect carbon nitride anchored iron atom cluster catalyst and a preparation method and application thereof, and belongs to the technical field of catalysts. Iron atoms are anchored in a carbon nitride (Ov-C3N4) structure containing oxygen vacancy defects in a cluster form, and Fe-Ov-C defect bonds are formed between the oxygen vacancy defects in C3N4 and iron atom clusters to stabilize the iron atom clusters, so that the problem of thermodynamic instability of the catalyst is solved while higher atom utilization efficiency is obtained; the Fe-Ov-C defect bond atoms can reasonably regulate and control the electronic structure of the center of an iron cluster d band, so that the catalytic activity and the cycling stability are greatly enhanced; besides, iron atom clusters and persulfate act to cause O-O bond breakage, non-free radical singlet oxygen is formed, and the problem that the catalytic efficiency is sharply reduced due to free radical annihilation in a complex water environment can be effectively solved.

The invention discloses a barium ion single-doped / double-doped brookite titanium dioxide nanorod catalyst as well as preparation and application, the catalyst synthesized by a thermal decomposition method comprises brookite phase titanium dioxide and doped barium ions, and the nanorod-shaped catalyst containing oxygen vacancy defects has the width of 4-6 nanometers and the length of 20-50 nanometers. The piezoelectric property of brookite titanium dioxide is induced through doping of barium ions, charge separation is promoted through a built-in electric field, meanwhile, oxygen vacancies are induced through a charge compensation mechanism, the piezoelectric catalysis and photocatalytic efficiency is promoted, and the problems mentioned in the background technology are solved.

According to the preparation method and the application of the high-nickel positive electrode material with the core-shell structure, the deep charge-discharge specific capacity and the cycling stability of the layered positive electrode material are remarkably improved by controlling the calcination condition of the high-nickel positive electrode material in an oxygen-free environment, regulating and controlling the oxygen vacancy on the surface of the material and synthesizing the sample with the core-shell structure. Meanwhile, the method is simple, effective and low in cost, and the prepared material is good in morphology uniformity and suitable for large-scale production.

The invention discloses a preparation method of a defect-rich metal organic framework (MOF)-based composite solid electrolyte and an all-solid-state battery application. The preparation method comprises the following steps: treating MOF under different atmospheres and temperatures to obtain oxygen vacancy defects with different concentrations; and introducing the MOF rich in defects as a filler into the polymer-based electrolyte slurry for treatment to prepare the composite solid electrolyte membrane. The defect-rich MOF-based composite solid electrolyte is innovatively constructed, the defect MOF has a synergistic effect with a porous structure through the ultrathin characteristic of the defect MOF, rapid transfer of interface charges and desolvation of Li < + > due to a strong confinement effect generated by a pore wall on Li < + > are facilitated, and high-selectivity transportation of Li < + > is realized; the solid-state electrolyte prepared by the preparation method provided by the invention has the advantages that the solid-state electrolyte is stable and stable, the dissociation of lithium salt is promoted by high-activity catalytic sites, a stable and uniform thin SEI layer is formed on the surface of an electrode, and the provided solid-state electrolyte effectively solves the problem of non-uniform deposition / stripping of a lithium metal battery in a cycle process and has excellent ionic conductivity and cycle stability.

The invention belongs to the technical field of catalytic materials, particularly relates to an electrocatalytic anode oxygen evolution reaction catalyst based on an anion exchange membrane electrolytic cell, and particularly relates to a high-entropy oxide electrocatalyst and a preparation method thereof. The high-entropy oxide electrocatalyst is composed of five metal elements of Ni, Co, Fe, Mn and Al, is loaded on a foamed nickel substrate, has a nanosheet structure, is rich in oxygen vacancies on the surface, has excellent electrochemical catalysis performance and stability, and is suitable for electrocatalysis of an electrolytic water anode side in an alkaline environment. According to the preparation method of the high-entropy oxide electrocatalyst, foamed nickel is used as a substrate, salts of five metals of Ni, Co, Fe, Mn and Al which are equal in mole are subjected to hydrothermal synthesis to form a precursor, and then the high-entropy oxide electrocatalyst is prepared through self-etching, annealing oxidation and acid etching, and the high-entropy oxide electrocatalyst is easy and convenient to operate, good in repeatability, controllable in cost, excellent in performance and suitable for large-scale production.

The invention relates to the technical field of catalytic materials, in particular to a molybdenum sulfide-based electro-catalytic material and a preparation method and application thereof. The invention provides a molybdenum sulfide-based electro-catalytic material, which comprises a transition metal chalcogenide containing chalcogen element vacancies and titanium dioxide quantum dots containing oxygen vacancies compounded on the surface of the transition metal chalcogenide, and a composite interface of the transition metal chalcogenide and the titanium dioxide quantum dots has a heterojunction structure. According to the composite electrocatalytic hydrogen evolution catalyst containing the TiO2 quantum dots and coupled with the double vacancies and the preparation method of the composite electrocatalytic hydrogen evolution catalyst, through the quantum effect and the double vacancy defect effect of the TiO2 quantum dots, the conductivity and the active site density of transition metal chalcogenide catalysts are improved, and the electrocatalytic hydrogen evolution performance is synergistically enhanced.

The invention discloses an electroreduction nitrate synthesis ammonia CuOx / CoOx nano material with an oxygen vacancy defect, and a preparation method and application thereof. In the CuOx / CoOx nano material, the molar ratio of a copper element to a cobalt element is 30: (1-8); the particle surface of the CuOx / CoOx nano material is provided with a nano-scale microporous structure; in the microstructure of the CuOx / CoOx nano material, the copper element coexists in the form of a Cu phase, a Cu2O phase and a CuO phase, and the cobalt element exists in the form of a CoO phase and a Co2O3 phase; the CuOx / CoOx nano material is prepared by adopting a coprecipitation method, a hydrothermal method and a calcination method. The CuOx / CoOx nano material is loaded on a cathode of an electrocatalytic reduction nitrate electrolytic tank for electrocatalytic reduction nitrate synthesis ammonia, and the efficiency of the electrolytic tank for catalyzing nitrate synthesis ammonia can be effectively improved.

The invention discloses a renewable alkane dehydrogenation catalyst as well as a preparation method and application thereof. The preparation method of the catalyst comprises the following steps: activating the molecular sieve carrier by adopting high-temperature heat treatment, mechanically and uniformly mixing the activated carrier with the active metal salt, the auxiliary metal salt and the alkali metal salt, and finally carrying out high-temperature oxidation treatment. And through high-temperature activation heat treatment, the pore structure of the molecular sieve is reconstructed, oxygen vacancies are introduced, rich defect sites are formed, then active metal is effectively anchored, and the metal-carrier interaction is optimized. Meanwhile, auxiliary metal and alkali metal are added to achieve a synergistic effect, sintering agglomeration of active metal is further inhibited, and the high-temperature stability and the recyclability of the catalyst are remarkably improved. The method is simple in process route, less in wastewater discharge and low in investment cost, the obtained catalyst is not inactivated after 50 times of circulation in propane dehydrogenation high-temperature reaction-regeneration, long-time sustainable use and recycling can be realized, and a new technical reference is provided for synthesis of novel industrial catalysts.

Hexavalent chromium (Cr (VI)) is widely applied to the industries of electroplating, spinning, leather tanning and chromium product manufacturing, and Cr (VI)-containing sewage has very strong biotoxicity and mutagenicity. Therefore, effective removal of Cr (VI) in industrial wastewater has important significance for protecting ecological environment and human health. As a novel bismuth-based oxychloride photocatalyst, the Bi4NbO8Cl material with the Aurivillius-Sillen structure has the advantages that the unique layered molecular structure of the Bi4NbO8Cl material is beneficial to the separation of photon-generated carriers, and the Bi4NbO8Cl material has good photocatalytic performance. On the basis of a Bi4NbO8Cl visible light response photocatalyst, the concentration of a glucose solution is regulated and controlled, carbon shell layers with different thicknesses are loaded, meanwhile, oxygen vacancy defects with different concentrations are formed, the visible light response Bi4NbO8Cl (at) C composite photocatalyst is obtained, and a good effect is achieved when the visible light response Bi4NbO8Cl (at) C composite photocatalyst is used for treating Cr (VI)-containing wastewater under the acidic condition.

The invention discloses a stannic oxide-based ammonia gas sensor as well as a preparation method and application thereof, relates to the technical field of gas sensors, and solves the problems of high detection lower limit, poor gas selectivity and low sensitivity of a traditional semiconductor ammonia gas sensor. A sensitive material based on oxygen vacancy regulation and control SnO2 / ZIF-67 is prepared on the surface of an interdigital gold electrode by adopting a chemical vapor deposition method, a planar electrode, an aluminum oxide ceramic substrate, a heater and a Pt wire are welded and packaged according to a general indirectly-heated gas sensitive element, and the SnO2 / ZIF-67 semiconductor ammonia gas sensor is prepared. The lower detection limit of the SnO2 / ZIF-67 semiconductor ammonia gas sensor is 1 ppm; meanwhile, the NH3 selectivity and sensitivity of the sensor are improved through the synergistic effect of SnO2 and ZIF-67, and the sensor can be used for detecting ammonia gas leakage and can be applied to judging the safety of ammonia gas in chemical production operation, environmental gas detection and other applications.

The invention provides a heterojunction-based multi-mode photoelectric synapse device and a preparation method thereof. The heterojunction-based multi-mode photoelectric synapse device comprises a bottom electrode, a memristive functional layer, a photosensitive layer and a top electrode which are stacked in sequence, the memristive functional layer comprises metal oxide rich in oxygen vacancies and is provided with a micro-nano structure surface; the photosensitive layer covers the surface of the micro-nano structure of the memristive function layer, and forms a heterojunction interface with the memristive function layer; the oxygen vacancies and the heterojunction interface act synergistically, so that the device can respond to changes of optical signals, ambient temperature and ambient oxygen partial pressure at the same time, and the optical pulse intensity and the optical response current generated by the device have a non-linear relationship. Through cooperative regulation and control of an oxygen vacancy and a heterojunction interface, the device can respond to changes of an optical signal, environment temperature and environment oxygen partial pressure at the same time, a non-linear relation exists between optical pulse intensity and optical response current generated by the device, and then the function of integrating multi-mode sensing and sensing storage calculation is achieved.

The invention discloses a catalyst applicable to preparation of methanol by hydrogenation of carbon dioxide and a preparation method of the catalyst, relates to the technical field of hydrogenation catalysts, and aims to solve the problems that active sites are few and sintering is easy at high temperature. The preparation method comprises the following steps: taking a Fe and Zn doped metal precursor and a main body Zr precursor as raw materials, preparing a gel catalyst intermediate product through a sol-gel method, carrying out supercritical drying, and then carrying out high-temperature calcination to prepare the Fe-Zn co-doped ZrO2 catalyst, and the activity of the Fe-Zn co-doped ZrO2 catalyst comes from rich oxygen vacancies and asymmetric active sites brought by metal doping; according to the invention, asymmetric active sites are constructed through metal doping to activate CO2, the prepared catalyst can realize more efficient reaction for preparing methanol through carbon dioxide hydrogenation at high space velocity in a high-temperature region, and the space-time rate of methanol can be directly increased by one order of magnitude.

The invention provides a surface modification method for a lithium-rich manganese-based positive electrode material, which comprises the following steps of: washing by using a peroxide-containing aqueous solution, properly increasing the washing temperature (preferably 40-80 DEG C), regulating the reaction pH value to 1-7, accurately controlling the ratio of acidity to free radical oxidation reaction, and optimizing the interface stability, oxygen vacancy density and Li < + > diffusion rate, thereby obtaining the lithium-rich manganese-based positive electrode material. Meanwhile, the dosage of peroxide (preferably persulfate) is reduced, the reaction time is shortened, the modification efficiency is improved, the raw material consumption is reduced, and the production cost is reduced.

A modified lithium-rich manganese-based positive electrode material, and a preparation method therefor and the use thereof. The modified lithium-rich manganese-based positive electrode material comprises a lithium-rich manganese-based positive electrode material, wherein the bulk phase of the lithium-rich manganese-based positive electrode material is doped with a high-valent transition metal element, and the surface phase of the lithium-rich manganese-based positive electrode material has a lithium metal compound coating layer and an oxygen vacancy. In the modified lithium-rich manganese-based positive electrode material, the doping with a bulk-phase high-valence transition metal element, the coating with a surface-phase lithium metal compound coating layer and the construction of an oxygen vacancy are conducted at the same time; and by means of the co-action of the three, the rate capability and the cycling performance of the lithium-rich manganese-based positive electrode material can be significantly improved, which is of great significance for the further commercialization of the lithium-rich manganese-based positive electrode material.