1632results about "Iron compounds" patented technology

The invention provides a lithium-rich lithium ferrite material and a preparation method and application thereof, the lithium-rich lithium ferrite material comprises a core layer and a carbon coating layer, the core layer is doped lithium-rich lithium ferrite, the chemical formula of the doped lithium-rich lithium ferrite is Li < 5 > Fe < 1-x > Al < x > O < 4 >, and x is 0.003-0.030. The lithium-rich lithium ferrite material is high in structural stability and excellent in conductivity; as a lithium supplement additive of a positive electrode active material, the composite material can improve electrochemical performance such as high-temperature storage performance and normal-temperature cycle performance of a lithium ion battery.

The invention relates to the technical field of wave-absorbing materials. Specifically, the invention relates to a ferrite composite multi-walled carbon nanotube wave-absorbing material and a preparation method thereof. The invention also relates to electronic equipment containing the ferrite composite multi-walled carbon nanotube wave-absorbing material. The ferrite composite multi-walled carbon nanotube wave-absorbing material prepared by the invention comprises a ferrite magnetic material with magnetic loss and a multi-walled carbon nanotube material with electrical loss, and the composite material introduces multiple electromagnetic energy loss modes through unique structural design and component synergy, so that the wave-absorbing performance of the material is enhanced. In addition, the preparation method disclosed by the invention is simple in process, low in requirement on equipment, green and environment-friendly, and free from any toxic and harmful by-products.

A lithium manganese iron phosphate material and a preparation method therefor, a positive electrode sheet and a preparation method therefor, and a battery. The structural formula of the lithium manganese iron phosphate material is LiFexMnyA(1-x-y)PO4, wherein 0<x<1, 0<y<1, 0≤1-x-y≤0.2, and a doping element A is selected from at least one of Be, Ca, Mg, Ba, and Sr. The surface alkalinity value of the lithium manganese iron phosphate material is 10-150 μmol / g.

The invention discloses a lithium supplementing material and a preparation method thereof, and belongs to the technical field of lithium ion battery lithium supplementing materials. The lithium supplementing material has a spherical core-shell structure; the spherical core-shell structure sequentially comprises a lithium iron phosphate layer and a lithium-rich lithium ferrite layer from outside to inside. The lithium supplementing material is prepared by two steps: firstly, carrying out surface coating in a similar sol-gel mode to obtain a material precursor, and then carrying out heat treatment on the precursor to obtain the lithium iron phosphate coated lithium-rich lithium ferrite material; in the preparation process, tannic acid is introduced for modified coating, so that the lithium iron phosphate coated lithium-rich lithium ferrite material which is uniformly coated and has high lithium supplement efficiency, high stability and relatively high reversible capacity is obtained, and the prepared lithium supplement agent material shows excellent lithium supplement performance and charge-discharge performance in a lithium ion battery performance test. Meanwhile, the preparation method is simple to operate and beneficial to actual production.

The invention relates to a sodium ion battery, and belongs to sodium ion batteries. The battery cell of the sodium-ion battery comprises a positive plate, a negative plate and an electrolyte, the active material of the positive plate is carbon-coated aluminum-doped sodium ferric sulfate; the chemical formula of the aluminum-doped sodium ferric sulfate is Na < 2 + 2y > Fe < 2-x-y > Al < x > (SO4) 3, x is more than or equal to 0.01 and less than or equal to 0.05, and y is more than or equal to 0.1 and less than or equal to The particle size of the carbon-coated aluminum-doped sodium ferric sulfate ranges from 50 nm to 100 nm; the weight ratio of a carbon coating layer in the carbon-coated aluminum-doped sodium ferric sulfate is 1%-5%; the active material of the negative plate is carbon-coated sodium titanate; the specific surface area of the carbon-coated sodium titanate is 20 m < 2 > / g to 25 m < 2 > / g; the weight ratio of a carbon coating layer in the carbon-coated sodium titanate is 0.5%-3%. Volume expansion is jointly inhibited through structural stability of positive and negative electrode materials, and the cycle life is prolonged.

The invention discloses a high-stability layered oxide sodium-ion battery positive electrode material and a preparation method thereof.The high-stability layered oxide sodium-ion battery positive electrode material comprises a layered oxide matrix and a surface coating layer, a sodium source, a nickel source, a manganese source, a lithium source and a magnesium source are mixed according to the stoichiometric ratio, a pre-sintered product is heated to 850-950 DEG C at the speed of 0.5-2 DEG C / min to be calcined, and the high-stability layered oxide sodium-ion battery positive electrode material is obtained. The calcined product, lithium phosphate and aluminum nitrate are subjected to ball milling and mixing in a citric acid solution with the pH value of 3-5 according to the mass ratio of 1: (0.005-0.03): (0.002-0.02), and the capacity retention ratio of the battery is larger than or equal to 88% after 500 times of circulation under the voltage range of 2.0-4.0 V and the multiplying power of 0.5 C. The comprehensive protection from the bulk phase to the interface is realized by triple doping and gradient coating, and the cycle life is prolonged by two times. Interlayer spacing expansion and coating layer ion conduction cooperate to reduce polarization, and the applicable temperature range is widened to-30 DEG C to 60 DEG C. Seed crystal induction and segmented sintering ensure batch consistency, and the method is suitable for large-scale production. Cheap Fe / Mn is adopted to replace part of Ni, and the material cost is reduced by 40% compared with similar products.

The invention belongs to the field of lithium ion battery materials, and discloses a precursor of a lithium-rich manganese-based positive electrode material and a preparation method and application thereof.The precursor comprises a core and a coating layer coating at least part of the surface of the core, the core is Mn2Oy, and y is larger than or equal to 2 and smaller than or equal to 3; the coating layer is MnX2O4, and X is any one or more than two of Fe, Co and Zn. The Li2XMn3O8 coated lithium-rich manganese-based positive electrode material is generated by lithiating and sintering the precursor, and the Li2XMn3O8 has a spinel structure and is perfectly connected with a layered structure of the lithium-rich manganese-based positive electrode material, so that the positive electrode material has good structural stability and high voltage resistance, and the electrochemical stability of the lithium-rich positive electrode material can be effectively improved.

A lithium manganese iron phosphate cathode material, including a first lithium manganese iron phosphate particle and a second lithium manganese iron phosphate particle. A molar ratio of Mn to Fe in the first lithium manganese iron phosphate particle is greater than or equal to 1. A molar ratio of Mn to Fe in the second lithium manganese iron phosphate particle is smaller than or equal to the molar ratio of Mn to Fe in the first lithium manganese iron phosphate particle. A particle size of the first lithium manganese iron phosphate particle is smaller than or equal to a particle size of the second lithium manganese iron phosphate particle. A preparation method of the lithium manganese iron phosphate cathode material and an application thereof are provided. The first precursor, having a manganese content greater than or equal to that of iron, inhibits crystal growth during sintering, resulting in a smaller particle size. The second precursor, having a manganese to iron ratio smaller than or equal to the ratio in the first precursor, promotes crystal growth during sintering, resulting in a larger particle size. This results in a particle size grading between large particles and small particles, improves the spatial utilization of particle packing, and enhances the compaction density and volumetric capacity of the lithium manganese iron phosphate cathode material.

The invention discloses a neodymium-zirconium co-substituted M-type strontium ferrite wave-absorbing material and a preparation method thereof, the chemical formula of the neodymium-zirconium co-substituted M-type strontium ferrite wave-absorbing material is Sr1-xNdxZr0. 2Fe11.8 O19, and x is more than or equal to 0.1 and less than or equal to 0.4. The method comprises the following steps: (1) mixing strontium nitrate, ferric nitrate nonahydrate, neodymium nitrate hexahydrate, zirconium nitrate pentahydrate, citric acid monohydrate and deionized water, stirring and dissolving to obtain sol; (2) adjusting the pH value of the sol to 6.5-7.5, and then heating to carry out sol-gel reaction to obtain wet gel; (3) drying and grinding the wet gel to obtain precursor powder; and (4) performing heat treatment on the precursor powder in a box-type furnace, cooling and grinding to obtain the neodymium-zirconium co-substituted M-type strontium ferrite wave-absorbing material. According to the material, effective wave-absorbing frequency band broadening is achieved, the matching thickness corresponding to the effective wave-absorbing bandwidth is as thin as 0.55-0.7 mm, and meanwhile, the performance requirements of thinness, width and strength in the field of electromagnetic compatibility are met.

The invention relates to the technical field of sodium ion battery positive electrode materials, and discloses a preparation method and application of a carbon-coated sodium ferric sulfate positive electrode material, and the preparation method comprises the following steps: (1) adding an iron source into an aqueous solution containing an organic acid, and stirring, the organic acid being ascorbic acid and / or citric acid; adding a sodium source or the sodium source and a sulfuric acid source, and stirring; (2) finally adding a carbon source, dropwise adding absolute ethyl alcohol while stirring, vacuumizing after dropwise adding, and continuously stirring for 2-4 hours to obtain a mixed solution; and (3) carrying out closed spray drying on the mixed solution, and calcining in an inert atmosphere to obtain the carbon-coated sodium ferric sulfate positive electrode material. According to the preparation method, coating of the carbon material is achieved in a closed spray drying mode, the conductivity of sodium ferric sulfate is greatly improved, in the whole preparation process, contact with oxygen is avoided, organic acid with an anti-oxidation effect is avoided, ferrous iron is prevented from being oxidized, and then the electrochemical performance can be further improved.

The invention belongs to the technical field of lithium ion batteries, and particularly discloses a metal organic framework packaged polyoxometallate coated ternary positive electrode material and a preparation method thereof. The preparation method of the ternary positive electrode material comprises the following steps: a) preparing metal A salt into a metal A salt solution; the preparation method comprises the following steps: preparing an ammonium molybdate compound into an ammonium molybdate compound solution, heating the ammonium molybdate compound solution to boiling, dropwise adding a metal A salt solution, and after dropwise adding, carrying out a constant-temperature reaction, filtering and recrystallizing to obtain Anderson type polyoxometallate; b) dissolving Anderson type polyoxometallate, a metal B salt and an organic ligand in water, and reacting at a certain temperature to obtain polyoxometallate packaged by a metal organic framework; and c) mixing a positive electrode material and the polyoxometallate packaged by the metal organic framework prepared in the step b) according to a ratio, and carrying out ball milling to obtain the ternary positive electrode material coated by the polyoxometallate packaged by the metal organic framework.

The invention discloses a preparation method of a multi-element doped ferromanganese oxide positive electrode precursor, and belongs to the technical field of lithium ion battery positive electrode material preparation. The molar ratio of manganese to iron in the multi-element doped ferromanganese oxide positive electrode precursor is x: (1-x), 0.2 lt; xlt; and the doping element accounts for 0.1-10% of the total mole number of manganese and iron. According to the multi-element doped ferromanganese oxide positive electrode precursor prepared by the invention, the coprecipitation intermediates are manganese carbonate and ferrous carbonate, and Ksp of the manganese carbonate and the ferrous carbonate are relatively close, so that the uniformity of ferromanganese can be ensured, meanwhile, metal ion doping is carried out in a liquid phase synthesis precursor stage, and the probability that doped ions enter compound lattices is greatly improved. The multi-element doped ferromanganese oxide positive electrode precursor has relatively high stability and good conductivity, and is beneficial to improving the capacity, the cycle life and the compaction density of a lithium iron manganese phosphate positive electrode material.

A lithium manganese iron phosphate substrate, cathode material, and their preparation method, as well as a lithium battery, belonging to the field of lithium-ion battery technology. The preparation of the lithium manganese iron phosphate substrate comprises the following steps: dissolving soluble ferrous salt, soluble manganese salt, phosphoric acid, and lithium hydroxide in deionized water to react, obtaining Material A; filtering Material A, taking the filter cake and drying it to obtain Material B; Heat treating Material B in an inert gas atmosphere to obtain the lithium manganese iron phosphate substrate. By coating the surface of the carbon-free nano lithium manganese iron phosphate substrate with metal oxides or metal salts and carbon, the coating layer formed on the surface of the composite lithium manganese iron phosphate material effectively prevents the reaction between the lithium battery and the electrolyte.

The invention discloses application of small molecules containing diphosphonic acid groups in preparation of hydrophilic inorganic nanoparticles, and relates to the technical field of preparation of inorganic nanoparticles. The method comprises the following steps: dispersing inorganic nanoparticles coated with a hydrophobic organic compound on the surface into tetrahydrofuran, dropwise adding into a small molecule solution containing a diphosphonic acid group, uniformly mixing, and adding diethyl ether to prepare the hydrophilic inorganic nanoparticles. The method is simple and convenient to operate, mild in condition, rapid in conversion, high in conversion rate, energy-saving and efficient, and the converted nano-particle freeze-dried powder is stable in property and easy to store and transport and has certain popularization value. The problems that in the prior art, an inorganic nanoparticle hydrophilic modification method is complex, and conversion efficiency is low are solved.

The invention provides a composite polyaluminum ferric chloride water purifying agent as well as a preparation method and application thereof, and belongs to the technical field of waste resource recycling and municipal sewage treatment. The industrial hazardous waste aluminum ash is subjected to innocent treatment and then reacts with the pickling steel waste liquid of the steel mill, and the polyaluminum ferric chloride meeting the industrial standard is prepared. The polyaluminum ferric chloride and a cationic adsorbent are compounded according to a specific proportion to obtain the composite polyaluminum ferric chloride water purifying agent. According to the method provided by the invention, the resource recycling of hazardous wastes is realized, and the composite polyaluminum ferric chloride water purifying agent obtained by the method is used for treating municipal sewage, so that the treated water quality can reach the first-grade discharge standard A.

The invention discloses a high-entropy doped manganese / iron-based layered material and a preparation method thereof, a pole piece and a battery, the material contains six different metal cations of manganese, iron, copper, titanium, lithium and magnesium in a transition metal layer, the material contains two different metal cations of sodium and calcium in a sodium layer, the chemical formula of the layered material is Na < 0.62 > Ca < 0.03 > Mn < 0.58 > Fe < 0.23 > Cu < 0.085 > Mg < 0.01 > Ti < 0.015 > Li < 0.08 > O < 2 >, the problem that the specific capacity is reduced and unstable in the prior art is solved.

The invention discloses a preparation method of a composite lithium-rich and lithium-supplement additive, which comprises the following steps: taking lithium ferrite as a core, preparing NiO (at) lithium salt by adopting an ALD atomic deposition method, fully and uniformly mixing carbon-coated lithium ferrite and the NiO (at) lithium salt, and sintering to prepare the composite lithium-rich and lithium-supplement additive. According to the invention, the advantages of high lithium supplement capacity of lithium ferrite, less gas production of lithium nickelate and good environmental adaptability are fully exerted, and the lithium supplement agent with high capacity and good stability is obtained; the nanometer nickel protoxide is in full contact with a lithium salt coating layer prepared by an ALD method, subsequent sintering is facilitated, preparation can be performed at a lower temperature, cost reduction is facilitated, meanwhile, the nickel protoxide and the peripheral lithium salt coating layer are subjected to a solid solution reaction, and residual lithium on the surface of lithium ferrite of a nuclear body can be obtained. The'two-channel lithium acquisition mode 'can reduce the overall residual alkali amount of the material, and is beneficial to improving the processing performance of subsequent battery slurry.

The application discloses a MnFe2O4 / GO wave-absorbing aerogel with a directional aperture structure and a preparation method thereof, belongs to the technical field of wave-absorbing material preparation, and is characterized in that manganese ferrite (MnFe2O4) magnetic particles are uniformly loaded on the surface of graphene to obtain a graphene aerogel with a three-dimensional loose porous structure and magnetic particle assembly; the MnFe2O4 is prepared by using a low-temperature co-precipitation method, and the MnFe2O4 / GO wave-absorbing aerogel is prepared by combining directional freezing and heat treatment, and the method is mild and simple. The application improves the impedance mismatch problem of the graphene material, enhances the magnetic loss of the material, and obtains a novel porous aerogel wave-absorbing material which has both dielectric loss and magnetic loss by introducing the manganese ferrite.

The invention relates to the technical field of water and soil remediation, in particular to magnesium-based hydrotalcite for treating multi-metal co-pollution as well as preparation and application of the magnesium-based hydrotalcite. The magnesium-based hydrotalcite laminate is customized by regulating and controlling trivalent metal elements and object interlayer anions of the magnesium-based hydrotalcite host laminate, the trivalent metal elements are one of Al (III), Fe (III) and the like, and the object interlayer anions are one of CO3 < 2->, NO3 <-> and the like. Preferably, the magnesium-based hydrotalcite is MgAl-CO3, MgAl-NO3, MgFe-CO3 or MgFe-NO3, and the magnesium-based hydrotalcite is a magnesium-based hydrotalcite or magnesium-based hydrotalcite. The LDHs-based material can mineralize heavy metal ions in an ultra-stable manner, and is suitable for rapidly, efficiently, stably and simultaneously removing various heavy metals, and mineralized products have extremely low Ksp (about 10-50), so that secondary pollution caused by secondary dissolution of the heavy metals is avoided.

A lithium-supplementing additive and a preparation method therefor, a positive electrode material, a positive electrode sheet, and a battery. The lithium-supplementing additive comprises a lithium-containing compound, the lithium-containing compound is selected from one or a combination of more compounds as represented by the following chemical formula: aLiFeαMnβM1-α-βO2-γXγ(1-a)Li2FeδMnεN1-δ-εO3-ηXη, where the element M and the element N are each independently selected from one or more of Zr, Co, Sr, Al, Ni, W, Ti, Cu, Mg, Zn, Ca, Ba, Sc, Ga, Y, La, In, Ce, Ge, Hf, Sn, Nb, Ta, V and Sb, the X is the element F, 0.4≤a≤0.9, 0<α≤1, 0≤β≤1, 0<α+β≤1, 0≤γ≤0.1, 0<δ≤1, 0≤ε≤1, 0<δ+ε≤1, and 0≤η≤0.1. The lithium-supplementing additive can stably and uniformly supplement lithium and improve the cycling stability.

The invention relates to the technical field of lithium ion battery materials, in particular to a preparation method of a manganese iron carbonate precursor and a lithium manganese iron phosphate positive electrode material, which comprises the following steps: preparing a mixed salt solution from a bivalent manganese salt and a bivalent iron salt; adding pure water and the mixed salt solution into a first-stage reaction kettle, preparing a reaction base solution, and adding a first precipitator into the first-stage reaction kettle to obtain a first reaction product; enabling the first reaction product to flow into a second reaction kettle through overflow, and adding a second precipitator to obtain a second reaction product; and enabling the second reaction product to flow into a slurry transfer tank through overflow, washing and drying the second reaction product to obtain a manganese iron carbonate precursor, mixing a lithium source, a phosphorus source, a carbon source and the manganese iron carbonate precursor, and sintering to prepare the carbon-coated lithium iron manganese phosphate positive electrode material. The primary particle size of the prepared manganese iron carbonate precursor can be less than or equal to 200nm, and the rate capability and the cycling stability of a positive electrode material lithium ion battery finally prepared by sintering are improved.

The invention relates to a metal oxide and application thereof. The metal oxide is of a face-centered cubic structure, the space group is Fd-3m, the lattice constant a of the metal oxide is # imgabs 0 # to # imgabs 1 #, and the tensile residual stress F1 in the metal oxide is 0.105 MPa to 5.51 MPa, or the compressive residual stress F2 in the metal oxide is 1.05 MPa to 8.6 MPa; the metal oxide is prepared by a spray pyrolysis method, and the pyrolysis rate K is 0.361 to 48.611. The metal oxide provided by the invention not only has relatively high crystallinity and stability, but also has high activity, and is beneficial to improving the intercalation of sodium ions or lithium ions when the positive electrode material is prepared, so that the comprehensive electrical property is improved.

The embodiment of the invention relates to a positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: putting a first lithium salt and a transition metal oxide into a zirconium oxide ball milling tank for wet milling to obtain a metal salt precursor; and performing heat treatment on the metal salt precursor in an inert atmosphere to obtain the lithium-rich cation disordered rock salt, placing the lithium-cation-rich disordered rock salt and a second lithium salt in a zirconium oxide ball milling tank for ball milling, so that a non-metallic element in the second lithium salt is inserted into a transition metal gap of the lithium-cation-rich disordered rock salt, thereby forming anions between an oxygen element and the non-metallic element of the lithium-cation-rich disordered rock salt, and obtaining a positive electrode material; wherein non-metallic elements in the second lithium salt are in a cation valence state, and the ion radius is smaller than the lithium ion radius in the first lithium salt and the transition metal ion radius in the transition metal oxide.

The invention discloses an ethanol-regulated layered metal oxide, a preparation method thereof and an application of the ethanol-regulated layered metal oxide in preparation of a single-walled carbon nanotube by catalytic cracking of methane, alkali liquor and soluble metal salt containing Fe, Mo, Mg and Al are dropwise added into an alkaline ethanol aqueous solution to form a precipitate, and the ethanol-regulated Fe-Mo / MgAl-LDOs catalyst is obtained after aging, drying and calcining. The catalyst is applied to methane catalytic cracking to prepare the single-walled carbon nanotube. According to the technical scheme, the dispersity of active components in the layered metal oxide is effectively improved, the layered metal oxide has larger specific surface area and pore diameter, but the pore volume is reduced, and the situation that growth of SWCNTs stops due to wall collision in the growth process is effectively avoided.

The invention discloses a fast-charging low-temperature graphite composite material, a preparation method and application thereof, the composite material is of a core-shell structure, the core is porous graphite and a carbon nanotube doped with the porous graphite, and the shell is composed of a lithium supplement agent and a lithium sulfonate complex of the lithium supplement agent. The preparation method comprises the following steps: soaking porous graphite in a conductive polymer solution, adding a catalyst, a cross-linking agent and an oxidizing agent, carrying out oxidative polymerization and carbonization to obtain catalyst-doped porous graphite, and introducing carbon source gas through a vapor deposition method to obtain carbon nanotube-doped porous graphite; and adding the obtained material into a lithium sulfonate solution, adding a lithium supplement agent, uniformly mixing, and carrying out spray drying to obtain the graphite composite material. According to the obtained material, the electronic conductivity of the material is improved by using the carbon nanotubes grown on the inner core, and the lithium sulfonate coated on the outer shell has relatively strong solvation capability, so that the transmission rate of lithium ions is improved, and the rate capability is improved; meanwhile, the lithium supplement agent releases lithium ions in the charging and discharging process, the first efficiency is improved, and the low-temperature and fast-charging performance is improved.

A low water content cathode material, a preparation method thereof, and a lithium-ion battery are provided. The low water content cathode material includes: a cathode material core, and an outer film layer being coated outside the cathode material core, in which, the outer film layer includes at least one carbon-based layer formed by an oxygen-free carbon source. In the preparation method, by coating a cathode material precursor with an oxygen-free carbon source, a resulting cathode material itself has a water content of 600 ppm or below and has the function of a protective film, such that the cathode material has low water absorption when exposed to a humid environment, and can improve the safety performance of a lithium-ion battery.

The invention discloses a ferrate nanocage superstructure material and a preparation method and application thereof, the preparation method comprises the following steps: preparing a zinc-iron Prussian blue nanocube precursor material, then dispersing the precursor material in deionized water, and standing and aging for 24-120 hours at 15-45 DEG C to obtain a zinc-iron Prussian blue nanocage; the preparation method comprises the following steps of: dispersing in diluted hydrochloric acid, adding metal salt, uniformly stirring, standing and reacting for 6-48 hours at the temperature of 50-120 DEG C, filtering, washing, drying, and annealing for 1-5 hours at the temperature of 300-500 DEG C; according to the invention, the zinc-iron Prussian blue nanocube is used as a precursor, the zinc-iron Prussian blue nanocage is obtained through aging, and the ferrite nanocage superstructure material is prepared through ion exchange and has excellent gas-sensitive characteristic.

The invention discloses a method for ultrafast synthesizing pyrochlore type and perovskite type oxides based on Joule heat, which comprises the following steps of: firstly, obtaining a solid precursor by adopting a coprecipitation method, then quickly heating the solid precursor to 700-800 DEG C by using a Joule heat shock technology, cooling to room temperature, and circulating heating-cooling operation for a plurality of times to prepare a series of pyrochlore type (A2B2O7) and perovskite type (ABO3) oxides; the synthesis time is extremely short (lt; the method has the advantages of high yield (more than 2500g / h), high energy efficiency and potential to realize the purpose of high-flux synthesis, and has a good industrial production basis and a wide application prospect.

The invention belongs to the technical field of photocatalytic materials, and particularly relates to a manganese ferrite / bismuth tungstate heterojunction photocatalyst as well as a preparation method and application thereof. The preparation method comprises the following steps: 1) dissolving sodium tungstate dihydrate, bismuth nitrate pentahydrate and hexadecyl trimethyl ammonium bromide in deionized water, and obtaining bismuth tungstate by using a hydrothermal method; 2) dissolving ferric chloride hexahydrate and manganese chloride tetrahydrate in water, then adding a sodium hydroxide solution, and obtaining manganese ferrite by using a hydrothermal method; and 3) dissolving bismuth tungstate and manganese ferrite into a sodium hydroxide solution, stirring, and drying to obtain the manganese ferrite / bismuth tungstate heterojunction photocatalyst. The formation of the heterojunction can greatly improve the activity of the manganese ferrite / bismuth tungstate in photocatalytic reduction of carbon dioxide.

The invention discloses lanthanum ferrite with a hollow porous microsphere structure as well as a preparation method and application thereof, and belongs to the technical field of gas sensitive materials. The lanthanum ferrite (LaFeO3) material is synthesized by adopting a hydrothermal method and heat treatment combined method, and the obtained lanthanum ferrite (LaFeO3) material can work under a high-temperature condition, so that the gas-sensitive property of the material is effectively improved. Meanwhile, the synthesis process is simple, the repeatability is good, the practicability and economical efficiency are high, and the high reference and application value is achieved in the field of preparation and research of gas sensitive materials; the problems that a traditional lanthanum ferrite preparation method is tedious, time-consuming and high in cost, and prepared lanthanum ferrite (LaFeO3) is low in cation and oxygen vacancy containing capacity, poor in carrier transport and oxidation reduction performance and the like are solved.