22 results about "Mixed valent" patented technology

The invention discloses a mixed valence copper doped bismuth vanadate nanodisk photocatalyst and a preparation method and application thereof, a main body of the catalyst is a bismuth vanadate nanodisk, copper is doped in the bismuth vanadate nanodisk, and the copper is composed of Cu < + > and Cu < 2 + >; the catalyst has the characteristics of high stability, simplicity in implementation, high universality and the like. The doped copper ions not only can improve the light absorption capacity of the bismuth vanadate material, but also can promote the rapid separation of photo-induced electrons and holes of the bismuth vanadate material by virtue of the mixed valence state of the copper ions, and improve the carrier dynamics on the material, so that the photocatalytic efficiency of the bismuth vanadate material is improved. The bismuth vanadate photocatalyst doped with the copper ions in the mixed valence state has an efficient photocatalytic degradation effect on pollutants such as rhodamine B and the like, and has a wide application prospect in the technical aspects of environmental pollutant degradation and green advanced oxidation.

The invention belongs to the technical field of carbon monoxide catalysts prepared through CO2 thermocatalytic hydrogenation, and provides a high-entropy oxide catalyst based on precursor valence engineering and a preparation method and application thereof. The catalyst is a CuZnMgNiCo-O high-entropy oxide with a rock salt crystal structure, Co exists in a Co < 3 + > / Co < 2 + > mixed valence state form, and the catalyst is prepared from Co2O3 through mechanical ball milling and a high-temperature solid phase method. According to the method, high-concentration oxygen vacancies are successfully constructed in situ in the catalyst, the ratio of Co < 3 + > to Co < 2 + > is optimized, and a rich HEO / Co3O4 phase interface is formed. The prepared catalyst shows excellent performance far superior to that of a CoO derivative catalyst in a reverse water gas shift reaction, has high CO2 conversion rate, CO selectivity close to 99%, apparent activation energy as low as 43 kJ / mol and excellent thermal stability, and provides a high-performance and easily-prepared catalytic material for efficient resource utilization of CO2.

The invention belongs to the technical field of water electrolysis hydrogen production energy conversion, and particularly relates to a molybdenum oxide-nickel molybdenum based compound water electrolysis hydrogen production catalyst material and a preparation method thereof. The method comprises the following steps: preparing a molybdenum oxide nanofiber substrate by adopting an electrostatic spinning technology in combination with pre-oxidation treatment; introducing a mixed valence state and oxygen vacancy defect into the substrate through a double-temperature-zone molybdenum vapor doping technology; performing bombardment treatment on the doped substrate by using argon-hydrogen low-temperature plasma to activate the surface; a nickel-molybdenum-based compound grows in situ on an activated substrate through a soaking crystallization method, and a final catalyst material is obtained through reductive heat treatment. The material has a unique three-dimensional hierarchical structure, a large specific surface area and abundant active sites. When being applied to a water electrolysis hydrogen evolution reaction, the catalyst shows excellent catalytic activity and stability under an alkaline condition, hydrogen evolution overpotential and electrolysis energy consumption can be remarkably reduced, the preparation process is controllable, the raw material cost is low, and the catalyst has a good application prospect.

The invention discloses a cobalt-doped ruthenium dioxide nanoparticle material as well as a preparation method and application thereof, and relates to a ruthenium dioxide nanoparticle material as well as a preparation method and application thereof. The nano-particle cluster is formed by irregularly distributing nano-particles; the nanoparticles have a single-phase crystal structure, and the spacing distribution of {110} crystal faces is 0.315 nm; the material is composed of three elements of Co, Ru and O, wherein Co is doped into RuO2 to form Co < 0.3 > Ru0. 7O2 nanoparticles; the material is of an octahedral structure, and Ru sites are replaced by Co doping; the chemical valence state of Ru on the surface of the material is a mixed valence state of + 3 and + 4; charge transfer occurs among three ions of Co, Ru and O, so that Ru is in a lower oxidation state. The cobalt-doped ruthenium dioxide nanoparticle material is used for electrolyzing water to produce hydrogen, and shows 2500-hour long-term stability under the current density of 10 mAcm <-2 >.

The invention belongs to the field of crystalline materials, and relates to a CuI / CuII mixed valence bimetallic Cu / Eu-MOF catalyst, a preparation method and catalytic application. The catalyst is a metal-organic framework catalyst constructed based on pyridine carboxylic acid ligands and copper / europium bimetal ions, the chemical formula is {[(CuI3I2) 4 (CuII2EuIII) 3L24 (H2O) 6] (NO3)} n, L is an organic ligand 5-chloronicotinic acid, and the catalyst is specifically formed by further connecting nanocages assembled by two different cluster base nodes of [Cu3I2] and [Cu2Eu (COO) 8] through organic ligands, the catalyst has complex mixed valence and Cu / Eu bimetallic synergistic catalytic sites, is high in porosity and large in specific surface area, is high in conversion yield of catalyzing reaction of CO2 and terminal alkynol compounds under mild conditions, and can be recycled for multiple times.

The invention discloses a preparation method of an element mixed valence state doped lithium-rich manganese-based positive electrode material, and belongs to the technical field of lithium ion batteries. The method comprises the following steps: synthesizing a sodium-based precursor with a layered structure in advance, jointly mixing the precursor with a lithium salt and a target dopant salt through an ion exchange step, and synchronously driving sodium-lithium ion exchange and partial oxidation of low-valence ions by virtue of a co-molten salt reaction system, so as to obtain the lithium ion battery. And finally, a stable valence state complementary doping structure is constructed at the atomic scale. According to the design, different valence states of the same doping element play a synergistic role in crystal lattices, high-valence-state ions can stabilize a crystal frame, and low-valence-state ions can adjust a local electronic structure and a coordination environment. According to the invention, lithiation, doping and valence regulation are realized in one step, and the prepared lithium-rich manganese-based positive electrode material has significantly improved coulombic efficiency, capacity retention rate and rate capability.

The invention belongs to the technical field of crystal catalytic material preparation and pollutant degradation, and relates to a CoSe nanocrystalline catalytic material as well as a preparation method and application thereof. The chemical formula of the CoSe nanocrystal is CoSe, the CoSe nanocrystal is formed by assembling Co atoms and Se atoms through covalent bonds, the crystal size is concentrated at 5-20 nm, and Co exists in a mixed valence of + 2 / + 3. The nanocrystal is synthesized in situ through controllable pyrolysis and gas-phase selenylation by combining coordination self-assembly with in-situ phase engineering. The CoSe nanocrystalline material is used as a peroxymonosulfate (PMS) activation catalyst for oxidative degradation of tetracycline.

This invention discloses a metallically modulated Mn-doped spinel-type ZnCo₂O₄ anode material and its preparation method, belonging to the field of lithium-ion battery electrode materials. The material maintains a pure-phase spinel crystal structure, exhibiting uniform and regular 2–5 μm polyhedral micron-sized particles with layered wrinkles and stepped porous structures on the surface. Mn and Co exist in mixed valence states of Mn²⁺ / Mn³⁺ and Co²⁺ / Co³⁺. First-principles DFT calculations confirm that Mn doping transforms the material from a semiconductor to a metallic conductor, eliminating the band gap, significantly increasing the Fermi level electronic state density, and reducing the lithium-ion diffusion barrier from 1.05 eV to 0.75 eV. Its preparation employs a hydrothermal method combined with a calcination process. This material exhibits high reversible specific capacity at a current density of 0.1 A·g⁻¹, excellent capacity retention after 200 cycles, outstanding rate performance in the range of 0.1~1.0 A·g⁻¹, significantly reduced charge transfer resistance, and overall electrochemical performance far superior to pure-phase ZnCo₂O₄. It can be directly used as a negative electrode for lithium-ion batteries and has good application prospects in the field of lithium-ion batteries.

The present application relates to the technical field of probabilistic bit device, and especially relates to a probabilistic bit device based on bias control and a preparation method thereof. The probabilistic bit device comprises an electrode pair and a probabilistic bit molecule, and the probabilistic bit molecule is connected between the electrode pair. The skeleton core is a symmetric or near-symmetric biferrocene group, and the two ferrocene units are equivalent redox active centers, and the redox potential is similar, which lays a foundation for state reversible switching and uniform charge delocalization. The ferrocene unit has excellent chemical stability and no thermal degradation problem; the intermediate bridging group can control the electronic coupling strength, which ensures the charge migration across the sites and avoids the coupling of the strong state merging. The results show that in the bias range of 260 mV-400 mV, the probabilistic bit molecule can be switched between the reduced state and the mixed valence state, and then the high and low state ratio of the device is changed, and finally a stable and controllable bias control type probabilistic bit device is constructed.

The invention belongs to the technical field of tetracycline degradation under visible light catalysis, and particularly relates to a transition metal doped bismuth tungstate photocatalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: adding a bismuth source, a tungsten source and an iron source into ethylene glycol, dispersing to obtain a first mixed solution, adding 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid and citric acid to adjust the mixed solution to be weakly acidic to obtain a precursor dispersion liquid, performing solvothermal reaction at 120-180 DEG C for 8-15 hours, washing, and drying to obtain the catalyst. The catalyst is bismuth tungstate nano-particles doped with an iron element and modified by the ionic liquid and has a hollow microsphere structure, the iron element exists in a mixed valence state of Fe < 2 + > and Fe < 3 + >, and the molar ratio of Fe to (Fe + Bi) is (0.25-0.75): 1. The catalyst disclosed by the invention is high in tetracycline antibiotic wastewater degradation efficiency under visible light, good in mineralization degree, strong in process adaptability and excellent in stability.

The application discloses a preparation method of cerium-doped goethite adsorption material and application thereof. The cerium-doped goethite adsorption material Ce-FeOOH is composed of metal cerium Ce doped goethite FeOOH; the Ce doping amount is 1.5-10.9 wt%, Ce is loaded on the surface of FeOOH in the form of mixed valence of Ce(III) and Ce(IV), and the proportion of Ce(III) is 17.8-30.0%. The Ce-FeOOH adsorption material maintains excellent adsorption stability in extracellular antibiotic resistance gene eARGs contaminated water bodies in a wide pH range and high ionic strength. The controllable doping method solves the problems of limited adsorption capacity and pH sensitivity of traditional materials, has high efficiency and economy in the treatment of eARGs pollution in a complex salinity water environment, and provides an innovative solution for water eARGs pollution control.

The invention relates to the technical field of Raman spectroscopy and nano materials, and discloses a preparation method and application of a surface-enhanced Raman scattering substrate, and the preparation method comprises the following steps: step 1, preparing a polydopamine modified nano tungsten bronze (MxWO) composite material: dispersing nano MxWO powder in a Tris buffer solution with the pH value of 7-9 to prepare a suspension with the mass concentration of 0.05-10wt%, and preparing a nano tungsten bronze (MxWO) composite material; performing ultrasonic treatment for 30-120 minutes in an ice-water bath at the power of 50-300 W, adding 0.1-1 g of dopamine hydrochloride, continuously performing ultrasonic treatment for 5-60 minutes, then performing magnetic stirring reaction for 4-12 hours at room temperature, and collecting precipitates; by virtue of a unique one-dimensional tunnel structure of nano tungsten bronze and a mixed valence state of tungsten, and in cooperation with a composite system constructed by polydopamine modification and metal nanoparticle introduction, efficient integration of an electromagnetic enhancement mechanism and a chemical enhancement mechanism is realized. The technical problems that a traditional precious metal substrate is high in cost and insufficient in stability and an oxide semiconductor substrate is limited in enhancement effect are solved.

The application belongs to the field of catalytic chemistry, and particularly relates to a Cu-Cu x O / C catalyst and a preparation method thereof, the catalyst is composed of a carrier carbon and an active component of copper and copper oxide with mixed valence, KBr is added as an inducer during Cu-MOF nucleation and growth, and the obtained sample is pyrolyzed at low temperature in a nitrogen atmosphere to obtain Cu-Cu x O / C. The prepared Cu-MOF derived mixed valence Cu-Cu x O / C catalyst can efficiently catalyze the electro-reduction of nitrate to ammonia.

This invention discloses a QCM gas-sensitive element based on electrospun Ce-MOF nanofibers and its preparation method, belonging to the field of gas sensing materials technology. The gas-sensitive element includes a quartz crystal microbalance substrate and a sensitive coating disposed thereon, wherein the sensitive coating is Ce-UiO-66 nanofibers; the Ce-UiO-66 nanofibers are prepared by electrospinning, with a diameter of 300-500 nm, and the cerium element is represented by Ce. 3+ / Ce 4+ It exists in a mixed valence state. This invention combines the high specific surface area adsorption characteristics of MOF with the rapid mass transfer advantages of porous fibers. The QCM gas-sensitive element has high sensitivity and rapid response characteristics to borneol volatile gases. Moreover, the QCM gas-sensitive element provided by this invention has a simple preparation process, low cost, and can operate at room temperature.

The present application relates to the technical field of composite fibers, in particular to a light-absorbing and heat-generating composite fiber and a preparation method thereof, and the preparation process comprises the following steps: (1) preparing core-shell structure light-absorbing and heat-generating particles; (2) modifying the surface of ferroferric oxide@silicon dioxide particles; (3) in-situ polymerization; and (4) melt spinning. In the present application, nano-ferroferric oxide is selected as a core light-absorbing material, and its unique Fe2+ / Fe3+ mixed valence electron structure can realize wide-spectrum light absorption while hardly generating oxidative photo-generated holes, thus avoiding the photocatalytic degradation risk similar to titanium dioxide from the source and ensuring the long-term stability of the polymer matrix. In combination with in-situ polymerization, axial gradient magnetic field spinning process and the like, the water washing resistance, aging resistance and strength of the light-absorbing and heat-generating composite fiber are simultaneously improved.

The application provides a noble metal catalyst with mixed valence, which comprises a carrier, noble metal and optional active metal. The content of noble metal in the catalyst is 0.01-20% of the total weight of the carrier, and the valence of the noble metal includes three or more than three of zero valence, one valence, two valence, three valence and four valence in X-ray photoelectron spectroscopy analysis. The application can accurately obtain the valence characteristics and corresponding content proportion of the noble metal on the catalyst surface, and further obtain the influence law of the valence characteristics and corresponding content proportion of the noble metal on the catalyst performance. In addition, the content of the noble metal with different valence on the catalyst surface can be controlled by changing the type, proportion and preparation conditions of the carrier, the additive and the modifier, so that the reaction performance of the catalyst is improved.

The application belongs to the technical field of sewage treatment, and relates to a core-shell structure C@Co / NF electrode material and a preparation method and application thereof, and an EC-C@Co / NF-PMS system. The electrode material takes foamed nickel as a three-dimensional conductive substrate, and a core-shell structure of carbon-embedded cobalt element is uniformly and densely grown in situ on the surface of the foamed nickel. Four elements of C, O, Ni and Co are uniformly distributed in the C@Co / NF electrode material, wherein the atomic percentage content of carbon is the highest and exceeds 50%, Co element is mainly Co 0 , Co 3+ and Co 2+ two mixed valence states are introduced, Ni element is mainly Ni 2+ , and the metal nickel Ni 0 of the substrate itself is reserved. The electrode material has high conductivity, high catalytic activity (excellent degradation capacity), strong stability, good economy and environmental friendliness, can efficiently electroactivate PMS and deeply degrade organic pollutants such as SMX in water.

The application relates to a preparation method and activity verification method of a mixed valence MOF material with laccase activity. The application belongs to the field of biomimetic catalysis. The application aims to solve the technical problem of low catalytic activity of existing laccase enzyme simulation materials. The application designs a kind of Cu + / Cu 2+ The application has the advantages of simple process, mild conditions, and the obtained Cu + / Cu 2+ The HKUST-1 material has higher laccase activity than the current Cu 2+ The enzyme simulation material has the potential of higher laccase activity, the catalytic activity of 2,3-dichlorophenol is up to 1.4 times that of the equal mass commercial laccase, has the advantages of high efficiency and low cost, and has good industrial application prospect. The application can be widely used for oxidizing phenolic compounds.

The invention belongs to the technical field of lithium ion batteries, and discloses a mixed ion conductor material and a preparation method and application thereof. According to the mixed ion conductor material LixAlyTi2-y (PO4) 3, the crystal structure is an orthogonal lattice, an independent Al / TiO6 octahedron exists in the mixed ion conductor material LixAlyTi2-y (PO4) 3, oxygen atoms at six vertexes in the octahedron are shared with a PO4 tetrahedron, and a continuous cavity channel is formed by a continuously combined structural unit Al / Ti2 (PO4) 3; due to a unique crystal structure and rich lithium ions, the material has ionic conductivity; the Ti element in the material is in a mixed valence state of III and IV valence, and the material has electronic conductivity due to continuous transition of electrons; therefore, the material disclosed by the invention has good ion conduction capability and electron conduction capability, is stable in structure, is endowed with excellent thermal stability and chemical stability, and can better exert the performance of the battery when being applied to positive electrode blending and positive electrode coating of the lithium ion battery.

The invention provides a doped corrosion-resistant dioxin-resistant silicon carbide wear-resistant ceramic material, and relates to the technical field of advanced ceramic materials, the material comprises, by weight, 80-95 parts of silicon carbide powder, 1-10 parts of a functional dopant, 2-8 parts of a sintering aid, 2-5 parts of a flexibilizer, 0.5-3 parts of a dispersant, and 0.5-10 parts of a binder. The core function dopant is core-shell structure nano-powder with an anatase TiO2 core and a mixed valence Ce / Sn silicate shell, and is prepared through sol-gel and heat treatment. On the basis of keeping high strength and high wear resistance of silicon carbide ceramic, the material is successfully endowed with long-acting and stable chemical corrosion resistance and high-temperature dioxin catalytic degradation capability, and the material is suitable for extreme environments such as waste incineration and chemical engineering.

The invention relates to the field of environmental materials, and discloses mixed valence manganese modified biochar and a preparation method and application thereof in synchronous passivation of cadmium and activation of selenium, and the mixed valence manganese modified biochar is mainly prepared through rice hull pretreatment, potassium permanganate pre-oxidation and segmented calcination. The invention relates to a porous carbon material of a mixed valence manganese oxide containing Mn3O4 and MnO2 at the same time. According to the method, chemical behaviors of cadmium and selenium in soil can be accurately identified and differentially regulated, and the bio-availability of selenium is remarkably improved while the ecological risk and plant absorption of cadmium are efficiently reduced.

The invention belongs to the field of heterogeneous catalysis, and discloses a preparation method and application of a two-dimensional flaky MOF material containing variable valence transition metal. The preparation method comprises the following steps: mixing a solution of a variable valence transition metal source of a vanadium source, a molybdenum source, an iron source or a cerium source with a solution containing imidazole organic ligands, and then reacting by a temperature-controlled solvothermal method to obtain M-MOF-T. Precise regulation and control of the mixed valence state of metal ions are achieved by regulating and controlling the solvothermal temperature, a vanadium-based MOF product forms a high-crystallinity two-dimensional sheet structure, and other metal-based MOF products all have highly-dispersed mixed valence state active centers. The catalyst shows excellent catalytic activity and selectivity on sulfur-containing compounds such as DBT, 4-MDBT and the like in fuel oil in a system taking ionic liquid [Bmim] BF as an extraction / reaction medium, the desulfurization rate of the vanadium-based catalyst on the DBT within 30 minutes reaches 100%, and the desulfurization rates of the molybdenum-based catalyst, the iron-based catalyst and the cerium-based catalyst exceed 78%; the reaction conditions are mild, the catalyst and the ionic liquid can be synchronously recycled, the process is simple, efficient and environment-friendly, and the industrial application potential is remarkable.