81 results about "Bismuth titanate" patented technology

The invention discloses a barium strontium titanate-based high-entropy energy storage ceramic with a core-shell structure, the barium strontium titanate-based high-entropy energy storage ceramic comprises SiO2 serving as a shell part and high-entropy ceramic powder serving as a core part, and the high-entropy ceramic powder comprises barium strontium titanate serving as a main phase and sodium potassium bismuth titanate serving as a high-entropy doping phase. The invention also discloses a preparation method of the barium strontium titanate-based high-entropy energy storage ceramic with the core-shell structure, which comprises the following steps: mixing and dissolving a carbonate raw material of a main phase and carbonate or oxide of a high-entropy doping phase, and stirring to form gel; removing organic components in the gel; calcining to form a perovskite phase to obtain high-entropy ceramic powder; sequentially dispersing in an acidic activator, a weakly acidic buffer agent and a weakly alkaline surfactant, adding a silicon source precursor, and heating to form a coating phase SiO2; and after sintering, annealing to obtain a final product. According to the barium strontium titanate-based high-entropy energy storage ceramic with the core-shell structure, the polarization intensity and the breakdown field strength of the ceramic can be improved at the same time.

The invention discloses a strontium-doped bismuth titanate-based ferroelectric film and a preparation method thereof, and belongs to the technical field of dielectric energy storage materials. The chemical composition of the film is Ba < 1-x > Sr < x > Bi < 4 > Ti < 4 > O < 15 >, wherein x ranges from 0.025 to 0.1. The preparation method comprises the following steps: mixing ethylene glycol monomethyl ether and ethylene glycol, adding bismuth nitrate, barium acetate, strontium acetate and butyl titanate, fully stirring and filtering to obtain a precursor solution, aging, dripping to the center of a substrate for spin coating, heating a spin-coated sample to obtain a dry film, and annealing to obtain the ferroelectric film. The method is low in technological condition requirement, and the thin film obtains the optimal energy storage density by changing the doping proportion of Sr. According to the ferroelectric film, when x is equal to 0.075, the leakage current density of Ba0. 925Sr0. 075Bi4Ti4O15 (BBST75) is only 1.59 * 10 <-7 > A / cm < 2 >, the breakdown field strength is as high as 3.22 MV / cm, and at the moment, the film has the energy storage density of 28.2 J / cm < 3 > and the energy storage efficiency of 80.36%.

The invention discloses lead-free piezoelectric ceramic with high mechanical quality factor and high vibration velocity stability and a preparation method of the lead-free piezoelectric ceramic, belongs to the field of functional ceramic materials, and particularly relates to the lead-free piezoelectric ceramic with the high mechanical quality factor and the high vibration velocity stability and the preparation method of the lead-free piezoelectric ceramic. The invention aims to solve the problems of low mechanical quality factor and poor high vibration velocity stability of the existing BNT-based ceramic. A two-step pre-sintering process is utilized, A2CO3 and B2O3 are introduced into sodium bismuth titanate ceramic at the same time, the pseudo perovskite piezoelectric ceramic is constructed through valence design, x in the formula represents the mole fraction, and x is larger than or equal to 0.01 and smaller than or equal to 0.08; the element A is selected from one of Ca, Sr and Ba with the ion valence state being divalent, and the element B is selected from one of Co, Sc, Ga, In, Cr, Mn and Fe with the ion valence state being trivalent. The high vibration velocity stability of the prepared lead-free ceramic is superior to that of lead-based ceramic, so that the lead-free ceramic has huge potential in the field of power type piezoelectric application.

The invention relates to the technical field of piezoelectric ceramics, in particular to a bismuth ferrite-lead titanate-zinc bismuth titanate ternary system piezoelectric ceramic material as well as preparation and application thereof. The chemical general formula of the bismuth ferrite-lead titanate-zinc bismuth titanate ternary system piezoelectric ceramic material disclosed by the invention is (1-x-y) BiFeO3-x (PbMez) TiO3-yBi (Zn0. 5Ti0. 5) O3, wherein Me is an alkaline earth metal element, x is equal to 0.4-0.8, y is equal to 0.05-0.3, z is equal to 0.05-0.5, and 1-x-y is greater than 0. The piezoelectric ceramic material has large anisotropy (d33 / d31 is between 5 and 60) and relatively high voltage (d33 is greater than 100pC / N), has a wide application prospect in the technical field of high-frequency image sonar transducers, and solves the problems of low piezoelectric coefficient and piezoelectric anisotropy of the existing bismuth ferrite-lead titanate-zinc bismuth titanate ternary system piezoelectric ceramic material.

The invention discloses a modified g-C3N4 heterojunction photocatalytic self-cleaning coating and a preparation method and application thereof.According to the coating, graphite phase carbon nitride g-C3N4 and bismuth titanate form an S-type heterojunction, the coating is of a lamellar structure, and the outermost layer is coated with polydimethylsiloxane; the preparation method comprises the following steps: (1) carrying out hydrothermal reaction on bismuth titanate and graphite phase carbon nitride to obtain a graphite phase carbon nitride nanosheet / bismuth titanate nanosheet S-type heterojunction photocatalyst; and (2) coating the surface of the catalyst with a polydimethylsiloxane prepolymer to obtain a product. The graphite-phase carbon nitride nanosheet is combined with bismuth titanate, and an S-shaped heterojunction is constructed, so that the utilization efficiency of solar visible light is remarkably improved, an oxidation-reduction reaction can be efficiently catalyzed under the irradiation of visible light, organic pollutants on the surface of the coating can be decomposed, and the coating has a self-cleaning capability by coating polydimethylsiloxane; and the removal cost of the organic pollutants is reduced.

The invention relates to a preparation method of a Cu-Pd alloy modified Bi4Ti3O2 nanorod, which comprises the following steps: 1) uniformly mixing and dissolving bismuth nitrate pentahydrate, tetrabutyl titanate and hexadecyl trimethyl ammonium bromide in a sodium hydroxide solution to obtain a milk white suspension; then putting the mixture into an anti-corrosion lining layer autoclave to react for 24 + / -10 hours at 180 + / -20 DEG C, washing and drying a product, and collecting; 2) dispersing the product in deionized water, performing ultrasonic treatment, adding a certain amount of copper nitrate trihydrate and palladium nitrate dihydrate, dropwise adding 0.08-0.12 mol L <-1 > sodium borohydride, and stirring to ensure that the reagent is completely dissolved; finally, washing the obtained sample for multiple times, and drying at 70 + / -15 DEG C to obtain a CuxPdy-BTO sample; according to the invention, two metal salt materials are dissolved in a precursor at the same time for a reduction reaction, and multiple metal salts are used for synthesizing the single / multi-metal modified bismuth titanate nano material.

The invention discloses a texture preparation method for high-performance lead-free piezoelectric ceramics of bismuth ferrite-barium titanate. The general formula of the ceramic composition is as follows, where the molar fraction ratio of BiFeO3 and BaTiO3 is 2:1, x, y, t, and m all represent molar fractions, and 0 < x ≤ 0.05, 0 < y ≤ 0.05, 0 < t ≤ 0.05, 0 < m ≤ 0.05. In the sintering stage of the invention, a temperature gradient field is constructed to make the ceramic grains grow texture-directionally, and a textured piezoelectric ceramic with a piezoelectric constant d 33 reaching above 1000 pC / N at 350 °C and a T dr reaching above 350 °C is obtained. The preparation process of the invention is simple, and the prepared ceramic has excellent high-temperature performance and can be applied to the field of high-temperature piezoelectricity.

The invention relates to the field of functional ceramics, in particular to a bismuth titanate-based high-entropy flexible material as well as a preparation method and application thereof. The chemical formula of the bismuth titanate-based high-entropy flexible material is Bi < 4-4x > (LaNdPrSm) < x > Ti < 3 > O < 12 >, and x is less than or equal to 0.75. Different elements are introduced to the Bi position of a ferroelectric material Bi4Ti3O12 to regulate and control the configuration entropy of a system, so that the obtained bismuth titanate-based material overcomes the brittleness problem of a traditional ceramic film material, shows excellent flexibility of folding without breakage, and has a dielectric constant and temperature stability superior to those of a traditional polymer-based flexible dielectric material; the method can be used as a dielectric capacitor in the flexible wearable field and the like, meanwhile, the method provides a solution for flexible preparation of the ceramic material, and the application field of the ceramic material is expanded.

The application discloses a low-loss high-Curie-point bismuth ferrite-barium titanate lead-free piezoelectric ceramic material and a preparation method thereof. 1.02 FeO3-(0.25-x)BaTiO3-xCaZrO3+y%GeO2+z%MnO2; wherein x, y and z represent molar fractions, 0.005<=x<=0.020, 0.3<=y<=1, 0.5<=z<=1.5. The application introduces the third component CaZrO3, and adds GeO2 and MnO2, controls the crystal phase composition and the conductive carrier concentration, improves the microstructure, reduces the loss and improves the temperature stability, so that the Curie temperature, the depolarization temperature and the piezoelectricity are obviously improved. The lead-free piezoelectric ceramic material provided by the application has a simple synthesis process, and is expected to be applied to the preparation of high-temperature piezoelectric sensor devices.

The application discloses a Bi4Ti3O12 nanosheet piezoelectric catalyst and a preparation method and application thereof. Bi(NO3)3*5H2O, Ti(OC4H9)4 and Ta2O5 are used as raw materials to prepare a precursor through co-precipitation, NaCl and KCl are used as molten salts to mix the precursor, and then ball milling is carried out, the obtained powder after the ball milling is dried, and then a molten salt reaction is carried out, so that the product is obtained, and after washing and drying, the Bi4Ti3O12 nanosheet piezoelectric catalyst is obtained, and is successfully applied to piezoelectric catalytic degradation of rhodamine B. The prepared Bi4Ti3O12 nanosheet piezoelectric catalyst is a nanosheet with high purity and good crystallinity, and a high-activity exposed surface is beneficial to improving the transmission and separation of photo-generated charges, improving the piezoelectric catalytic performance of the Bi4Ti3O12 nanosheet piezoelectric catalyst, and the preparation process is simple.

The invention discloses a bismuth titanate / bismuth stannate / bismuth composite photocatalytic material, the structural formula of the bismuth titanate / bismuth stannate / bismuth composite photocatalytic material is Bi < 4 > Ti < 3-0.5 > x Sn < x > O < 12 > / Bi < 2 > Sn < 2 > O < 7 > / Bi, and the value of x is 0.05-0.5. The invention further discloses a preparation method of the bismuth titanate / bismuth stannate / bismuth composite photocatalytic material, Bi2O3, TiO2, SnO2 and NaCl-KCl molten salt are mixed, subjected to ball milling, dried and sintered, sintered powder containing molten salt is obtained, washed, centrifuged and dried, and the bismuth titanate / bismuth stannate / bismuth composite photocatalytic material is obtained. The Bi4 (Ti, Sn) 3O12 / Bi2Sn2O7 / Bi composite photocatalytic material prepared by the preparation method disclosed by the invention has high oxidation potential, high photon-generated carrier separation efficiency and high visible light absorption, can show excellent photocatalytic activity, and shows a good application prospect in the aspect of photocatalytic degradation of organic pollutants.

The present invention relates to a bismuth titanate niobate-based relaxor ferroelectric ceramic material for energy storage, a preparation method thereof and an application thereof. The relaxor ferroelectric ceramic material has the general formula Bi 3‑x La x TiNbO9, 0≤x≤1.1; this relaxor ferroelectric ceramic material is prepared by lanthanum-doping Bi3TiNbO9 using a solid-phase sintering method; the lanthanum doping is performed with lanthanum oxide. The present invention has the advantage that the resulting bismuth titanate niobate-based relaxor ferroelectric energy storage ceramic material effectively overcomes the low energy storage density and efficiency of conventional ferroelectric materials, especially bismuth layered ferroelectric materials, making the energy storage performance of the present invention significantly superior to that of undoped bismuth titanate niobate ferroelectric ceramics and other bismuth layered ferroelectric ceramic materials, while also having better working environment stability. The preparation method of the present invention is simple, the raw materials are readily available, and the production efficiency is high, making it suitable for large-scale practical production applications.

The invention discloses a bismuth titanate biomass charcoal composite material for environmental remediation and a preparation method thereof, and relates to the field of environmental functional materials.The composite material takes corncob biomass charcoal as a carrier, and bismuth titanate nanoparticles are loaded on the surface and in pores of the corncob biomass charcoal; the corncob biomass charcoal has a hierarchical porous structure, the specific surface area of the corncob biomass charcoal is not less than 1500 m / g, and the surface of the corncob biomass charcoal is rich in oxygen-containing functional groups; the bismuth titanate nanoparticles and the corncob biomass charcoal are tightly combined through a heterojunction interface; according to the bismuth titanate biomass charcoal composite material for environmental restoration and the preparation method of the bismuth titanate biomass charcoal composite material, firstly, pollutants are rapidly adsorbed and enriched to the periphery of bismuth titanate active sites through the high specific surface area and abundant pore structure of the corncob charcoal, local high concentration is formed, and favorable conditions are created for subsequent photocatalytic reaction; bismuth titanate generates strong oxidizing active oxygen species under excitation of visible light, and adsorbed pollutants are thoroughly degraded.

The application discloses a preparation method of a sheet-shaped Nb element doped modified bismuth titanate catalyst material. 3‑x Nb x O 12 , wherein 0.15<=x<=0.40, the molar ratio of Bi, Ti and Nb is taken as bismuth oxide, titanium dioxide and niobium pentoxide; step two: the raw materials in step one and the mass ratio of the molten salt are mixed, then the mixture is put into a crucible and fully grinded to obtain a mixture; step three: the mixture prepared in step two is fired in a muffle furnace, and a light yellow product is obtained after cooling; step four: the light yellow product prepared in step three is washed with deionized water, filtered and dried to obtain a sheet-shaped Nb element doped bismuth titanate catalyst powder. The technology can significantly improve the structural uniformity, defect concentration and piezoelectric response activity of the material, greatly reduce the energy consumption and time cost, provides an efficient path for large-scale production of high-performance catalysts, and has a wide market prospect.

The application relates to the technical field of nanometer materials, and particularly discloses a bismuth titanate nanometer material, a preparation method thereof and a sewage treatment method. The preparation method of the bismuth titanate nanometer material comprises the following steps: uniformly mixing bismuth oxide, titanium oxide, holmium oxide, sodium chloride and potassium chloride according to a molar ratio of Bi:Ti:Ho:NaCl:KCl=(3.5-3.92):(2.8-3.2):(0.1-0.5):(40-55):(40-55) to obtain a precursor; calcining the precursor to obtain an intermediate product; and removing sodium chloride and potassium chloride in the intermediate product. By implementing the application, the polarity and piezoelectric response of the bismuth titanate nanometer material can be improved, and the piezoelectric-optical catalytic performance of the bismuth titanate nanometer material can be improved.

The invention discloses a bismuth titanate and bismuth vanadate compounded high-performance photoelectrode and a preparation method thereof, and belongs to the technical field of electrode materials. The bismuth titanate composite bismuth vanadate high-performance photoelectrode comprises the BiVO4 layer, the BiVO4-x layer, the Bi4Ti3O12 layer and the NiCoBi layer, the bismuth titanate layer serves as a hole transport layer, the surface state is passivated, transport of carriers is promoted, recombination of surface charges is reduced, and the performance of the electrode is greatly improved; the NiCoBi layer improves the photo-corrosion defect of the material, the catalytic ability of water decomposition is improved, and the stability is obviously improved; and meanwhile, a heterojunction is formed between the BiVO4 layer and the Bi4Ti3O12 layer, so that the separation efficiency of photon-generated carriers is enhanced, and the high-performance photoelectrode with high stability, high carrier separation efficiency and high surface catalytic oxygen production efficiency is finally obtained.

The invention relates to the technical field of ceramic materials, and discloses a polybasic sodium bismuth titanate-based environmentally friendly ceramic with excellent comprehensive energy storage properties. The nominal chemical formula of the material is (100‑x‑y) mol% Na 0.5 Bi 0.5 TiO3‑xmol%BaTiO3‑ymol%Sr 0.8 Ca 0.2 Ti 0.9 Al 0.05 Ta 0.05 O3-zmol%La2O3, 6.5<x<9.5, 28<y<31, 0.5<z<1. In addition, the preparation process of the present invention is novel and relatively low in cost and environmentally friendly. The obtained ceramic capacitor material has excellent energy storage and charge-discharge characteristics, strong thermal stability, and good industrialization prospects.

This invention belongs to the field of biomedical materials technology, and relates to a piezoelectrically enhanced nanoenzyme composite material, its preparation method, and its antibacterial application. Cobalt-doped molybdenum disulfide is grown in situ on the surface of bismuth titanate nanosheets to obtain a BTO@Co-MoS2 composite material. This composite material exhibits a piezoelectric effect under pressure stimulation. Electrons, under the influence of the built-in electric field at the BTO@Co-MoS2 interface, promote the self-cycling of the molybdenum disulfide redox pair, thereby improving the catalytic activity of halogen-like peroxidases. Simultaneously, the piezoelectric catalysis of hydrogen peroxide generation alleviates the problem of insufficient endogenous hydrogen peroxide. In antibacterial applications, the piezoelectrically enhanced nanoenzyme composite material prepared by this invention achieves bactericidal rates of 98.39% and 99.95% against Staphylococcus aureus and Escherichia coli, respectively.

This invention relates to the field of piezoelectric ceramics technology, and in particular to a composite ion-modified bismuth layered bismuth titanate calcium-based high-temperature piezoelectric ceramic and its preparation method. The general formula for high-temperature piezoelectric ceramics is: Ca 1‑x (LiCe) x / 2 Bi 3.75 Nd 0.25 Ti 3.935 Sc 0.065 O 15 , where x is a complex high-valence ion (LiCe). 4+ Twice the molar amount, x = 0.02, 0.05, 0.08, 0.10. This invention employs the above-mentioned composite ion-modified bismuth layered bismuth titanate calcium-based high-temperature piezoelectric ceramic and its preparation method to meet the application requirements in high-temperature environments while ensuring the material's environmental friendliness.

The application relates to the technical field of catalysts, and particularly discloses a sulfur-tolerant shift catalyst as well as a preparation method and application thereof. The sulfur-tolerant shift catalyst provided by the application comprises the following components in parts by weight: a carrier, an active component and an additive; the carrier is an acid-modified attapulgite-bismuth titanate composite carrier; the active component is CoO and MoO3, and the loadings of the active component in the catalyst are 2-5 wt% and 8-12 wt% respectively; wherein, the preparation method of the acid-modified attapulgite-bismuth titanate composite carrier comprises the following steps: preparing an acid-modified attapulgite, preparing a bismuth titanate precursor solution, compounding and calcining and activating. The sulfur-tolerant shift catalyst provided by the application has the advantages of low preparation cost, high catalytic activity, good stability and the like, and has a good application prospect.

The invention belongs to the technical field of piezoelectric ceramics, and particularly relates to a high-temperature magnesium bismuth titanate-lead zirconate titanate piezoelectric ceramic material and a preparation method thereof. Comprising the following chemical general formula: 0.65 Bi (Mg < 0.51 > Ti < 0.49 >) O < 3 >-0.35 Pb (Zr < x > Ti < 1-x >) O < 3-y > wt% La2O3, wherein x is equal to 0.01 to 0.7, and y is equal to 0.01 to 2. The piezoelectric ceramic material is prepared from the following raw materials: Pb3O4, TiO2, ZrO2, Nb2O5, Bi2O3, MgO and La2O3. The novel piezoelectric ceramic system has higher Curie temperature of 460-520 DEG C, and can work in a high-temperature environment of 260-400 DEG C. The novel piezoelectric ceramic system is suitable for being applied to a high-temperature sensor piezoelectric device.

The invention provides high-reflection ultralow-temperature UV curing ink, a preparation method thereof and a photovoltaic module, and relates to the technical field of UV curing ink. The high-reflection ultralow-temperature UV curing ink is prepared from the following raw materials in percentage by mass: 50-70% of modified ink oil and 30-50% of glaze powder, wherein the total mass of the raw materials is 100%; the modified ink is prepared from the following raw materials: transparent resin, a high-reflection additive and an auxiliary agent; the glaze powder is prepared from the following raw materials: glass powder, titanium dioxide, bismuth titanate and Bi2Ti2O7 nanocrystals. The high-reflection ultralow-temperature UV curing ink has the advantages that the service life is prolonged, the good environmental protection performance is realized, and the environmental pollution in the production process is favorably reduced; through specific material combination, spectral selectivity is increased, and high reflection of light in a specific wavelength range can be realized, so that the optical performance of the photovoltaic module is optimized; and photo-thermal loss is reduced.

The invention discloses a bismuth layered sodium bismuth titanate high temperature piezoelectric ceramic material and a preparation method and application thereof. The general formula of the bismuth layered sodium bismuth titanate high temperature piezoelectric ceramic material is Na 0.5 Bi 4.5 Ti 4‑ x Nb x O 15+x / 2 :Sr, calculated by the amount of substance, Sr and Na 0.5 Bi 4.5 Ti 4‑x Nb x O 15+x / 2 The ratio is 0.02:1, 0.04≤x≤0.08. The dielectric loss of the bismuth layered sodium bismuth titanate high temperature piezoelectric ceramic material is 0.0037, the Curie temperature is 669℃, the piezoelectric constant is 31.5pC / N, and the mechanical quality factor is Q m is 3576, the electromechanical coupling coefficient k p The high temperature resistivity is 15.2% and the high temperature resistivity is 5.7*10 at 500℃. 7 Ω·cm, bismuth layered sodium bismuth titanate high-temperature piezoelectric ceramic materials have broad application prospects in the field of high-temperature piezoelectric devices.

The invention discloses an erbium and ytterbium co-doped calcium bismuth titanate dual-mode excitation up-conversion fluorescent anti-counterfeiting material and a preparation method thereof, the dual-mode excitation up-conversion fluorescent anti-counterfeiting material comprises an erbium and ytterbium co-doped calcium bismuth titanate light storage luminescent material, the chemical formula of the erbium and ytterbium co-doped calcium bismuth titanate light storage luminescent material is CaBi4 (0.97-x) Ti4O15: xEr < 3 + >, yYb < 3 + >, x is more than or equal to 0.005 and less than or equal to 0.1, and y is more than or equal to 0.1 and less than or equal to 0.4. The preparation method comprises the following steps: S1, weighing Bi2O3, Er2O3, Yb2O3, CaCO3 and TiO2 according to a stoichiometric ratio, and mixing and grinding the weighed materials into powder; and S2, sintering the powdery material obtained by grinding in the step S1 in a reducing atmosphere at the sintering temperature of 500-850 DEG C for 5-10 hours, then cooling to room temperature, and grinding the cooled material to obtain the erbium and ytterbium co-doped calcium bismuth titanate fluorescent powder CaBi4Ti4O15: Yb < 3 + > and Er < 3 + >. According to the calcium bismuth titanate dual-mode excitation up-conversion fluorescence anti-counterfeiting material disclosed by the invention, CaBi4Ti4O15 titanate is taken as a matrix to be double-doped with Yb < 3 + > and Er < 3 + >, so that the up-conversion luminescence performance and the fluorescence luminescence anti-counterfeiting performance are improved.

The invention belongs to the technical field of powder preparation by a wet chemical method, and provides a sodium bismuth titanate powder material and a preparation method thereof, the powder material is rhombohedral phase (Bi0. 5Na0. 5) TiO3, the particle morphology of the powder material is a nanocube, and the average size is 76nm. The (Bi0. 5Na0. 5) TiO3 nanocube is prepared through a two-step heating hydrothermal method, has the advantages of being simple in process, low in cost, good in stability and repeatability, capable of being produced on a large scale and the like, and has wide application prospects in the fields of sodium bismuth titanate, sodium bismuth titanate-based ferroelectric ceramics, barium titanate-based thermal sensitive ceramics and the like. The (Bi0. 5Na0. 5) TiO3 nanocube powder prepared by the invention is used as a raw material, (Bi0. 5Na0. 5) TiO3 ceramic sintered at 1100 DEG C for 4 hours has good sinterability and ferroelectricity, the relative density of the (Bi0. 5Na0. 5) TiO3 ceramic is 95% or above, and the maximum polarization intensity, the remanent polarization intensity and the coercive field of the (Bi0. 5Na0. 5) TiO3 ceramic are 40.02 mu C / cm < 2 >, 27.78 mu C / cm < 2 > and 87.5 kV / cm respectively.

The invention provides a piezoelectric catalyst and a preparation method and application thereof. The piezoelectric catalyst comprises a polymerized carbon nitride / bismuth titanate heterojunction. The piezoelectric catalyst is a bifunctional catalyst with high catalytic efficiency and high recycling rate, has the characteristics of simplicity in operation, low cost and environmental protection when being applied to degradation of organic pollutants, and has wide application prospects in the fields of wastewater pollutant degradation, environmental restoration and the like.

The invention discloses a polarized bismuth titanate / PPy positive electrode material for enhancing polysulfide adsorption, a preparation method and application of the polarized bismuth titanate / PPy positive electrode material in a lithium-sulfur battery, and the preparation method comprises the following steps: carrying out polarization treatment on a bismuth titanate nanosheet to obtain a polarized bismuth titanate nanosheet; the preparation method comprises the following steps: adding a pyrrole dispersion liquid and an oxidizing agent into an aqueous dispersion liquid of the polarized bismuth titanate nanosheets, and carrying out a polymerization reaction to obtain a polarized bismuth titanate / PPy composite material; sulfur nanoparticles are deposited on the surface of the bismuth titanate / PPy composite material by adopting a thiamine chemical method. The preparation method disclosed by the invention is simple in process, and the synthesized positive electrode material is uniform in component, good in crystal morphology and high in phase purity. The in-situ polymerized PPy greatly improves the conductivity of the composite material, so that the dissolution of polysulfide in electrolyte is inhibited, the shuttle effect is effectively reduced, and the electrochemical cycle stability of the lithium-sulfur battery is improved.

This invention discloses a yarn-like ball-shaped BaTiO3 / Bi4Ti3O 12 The preparation method of the catalyst material and the product obtained are described. An ethanol solution of flake-shaped bismuth titanate and tetrabutyl titanate, along with a barium salt solution, are stirred and mixed with an alkaline conditioning solution to obtain an alkaline suspension. After hydrothermal reaction, the suspension is acid-washed, washed, filtered, and dried to obtain yarn-like spherical BaTiO3 / Bi4Ti3O3. 12 Catalyst powder. The catalyst of this invention has a structure of hollow, woolen spheres assembled from nanowires, with nanoparticles embedded on the surface of the spheres. This effectively increases the contact area between the catalyst and the reactants, thereby improving the carrier separation efficiency in piezoelectric catalysis and greatly enhancing catalytic activity. The raw materials of this invention are inexpensive and the operation is simple, solving the problems of complex processes and high costs associated with the synthesis of one-dimensional catalysts or the need for templates and morphology modifications in existing technologies. The product can be applied in photocatalysis and piezoelectric catalysis, and has high application value.

The invention relates to a calcium bismuth titanate piezoelectric ceramic with a high piezoelectric constant and a piezoelectric voltage constant and a preparation method of the calcium bismuth titanate piezoelectric ceramic. The chemical composition of the bismuth calcium titanate piezoelectric ceramic is Ca < 0.94 > Bi < 4.06 > Ti < 4 > O < 15-x > wt% MgO, x represents the mass percent of MgO in a Ca < 0.94 > Bi < 4.06 > Ti < 4 > O < 15 > matrix, and x is greater than 0 and less than or equal to 0.3. The Ca0. 94Bi4. 06Ti4O15 component with good piezoelectric property is taken as a matrix, and MgO with low dielectric constant is added, so that the dielectric constant of the calcium bismuth titanate-based high-temperature piezoelectric ceramic is regulated and controlled; meanwhile, a built-in electric field can be established when the free moving charges are polarized, so that the polarization intensity is enhanced, and the piezoelectric property is improved.

The invention relates to a calcium bismuth titanate piezoelectric ceramic with high piezoelectric property and high-temperature resistivity and a preparation method thereof. The chemical composition of the bismuth calcium titanate piezoelectric ceramic is Ca < 1-x > Bi < 4 + x > Ti < 4 > O < 15 >, and x is the mole percent, 0 lt; x is less than or equal to 0.08. By designing the composition of the calcium bismuth titanate, replacing Ca < 2 + > with Bi < 3 + > and utilizing space charge polarization to improve the piezoelectric property, the piezoelectric property and the high-temperature resistivity of the calcium bismuth titanate piezoelectric ceramic are remarkably improved under the condition that the high Curie temperature of the calcium bismuth titanate piezoelectric ceramic is maintained, and the calcium bismuth titanate piezoelectric ceramic with high Curie temperature, high piezoelectric property and high direct-current resistivity is obtained. The requirements of the piezoelectric ceramic material for the high-temperature piezoelectric vibration sensor are met, and the application of the piezoelectric ceramic material in the high-temperature field is promoted.