215 results about "Electronic band structure" patented technology

An electrode structure for a solid-state or semi-solid-state battery is provided in which NCM electrode particles coated with an interphase layer and a nitrogen-containing carbon layer are disposed. [Solution] The NCM electrode particles comprise NCM (nickel-cobalt-manganese oxide) particles (15), primary particles (30) that coat the outer surfaces of the NCM particles, an interphase layer (16) that includes a glass phase layer (241) and a plurality of ceramic particles (242), and a nitrogen-containing carbon layer (35) that coats the exterior of the primary particles. Nitrogen-doped carbon molecules in the nitrogen-containing carbon layer aid in the conduction of electrons and lithium ions, modifying the electrical potential of the NCM particles. The nitrogen-containing carbon layer is formed by coating the surfaces of the primary particles with a nitrogen-containing polymer material and calcining the material in an inert atmosphere. Conjugated bonds are formed between the carbon and nitrogen, modifying the energy band structure, reducing the energy required for electrons to transition to the conduction band, and improving overall electronic conductivity.

The invention discloses preparation of a phenanthroline-based covalent organic framework photocatalyst and application of the phenanthroline-based covalent organic framework photocatalyst in photocatalytic production of hydrogen peroxide. According to the method, a hydrogen peroxide production experiment is carried out in a water-oxygen system or a benzyl alcohol-water-oxygen system by taking phenanthroline-based COF as a photocatalyst. According to the invention, through regulation and control of molecular flatness engineering, an electron-rich phenanthroline unit (Phen) anchored by a pyridine expansion plane and electron-deficient triazine (TTA) are integrated into a COF skeleton, and a novel electron donor-acceptor (D-A) type COF is synthesized. The COF has the advantages of proper energy band structure, excellent photo-induced electron and hole separation efficiency, strong D-A interaction, good hydrophilicity and the like, and the efficiency of photocatalytic hydrogen peroxide production reaction within a short time is greatly improved. The invention provides a use method of the COF photocatalyst which is cheap, convenient, rapid, efficient and environment-friendly, and has a potential application prospect.

The invention relates to a double-frequency filtering metasurface design method based on topological optimization. The method comprises the following steps: establishing a two-dimensional simulation model comprising a double-frequency filtering metasurface matrix and a scatterer; according to a preset target forbidden band, taking a forbidden band frequency covering frequency doubling target interval as a fitness function, coding the binary matrix representing material distribution as a chromosome to perform optimization iteration of the chromosome, and obtaining the chromosome with the maximum fitness function value; in optimization iteration, material distribution corresponding to chromosomes is constructed on a two-dimensional simulation model, an energy band structure of the two-dimensional simulation model is obtained, and a fitness function value is calculated; and according to the binary matrix of the chromosome with the maximum fitness function value, outputting final optimized material distribution of the double-frequency filtering metasurface, and performing performance verification on a result through simulation to obtain the double-frequency filtering metasurface of which a fundamental frequency wave can be blocked through a double-frequency wave. Compared with the prior art, systematic optimization of the frequency doubled sound filtering scene is realized.

The invention belongs to the technical field related to structure optimization design, and discloses a topological optimization method and device for a metamaterial microstructure capable of bearing a band gap, and the method comprises the steps: (1) respectively defining an interpolation penalty coefficient of a Young modulus for the homogenization analysis of the microstructure and the band gap problem of an energy band structure according to the performance analysis of the microstructure, calculating an interpolation penalty coefficient of the mass density; (2) carrying out homogenization analysis of the microstructure based on dynamics to obtain equivalent physical property parameters and determine equivalent material modulus; (3) defining an irreducible first Brillouin region wave vector path of the microstructure based on the geometric symmetry constraint of the microstructure, and further calculating a band gap quality factor between adjacent energy band curves of the microstructure; and (4) establishing a topological optimization model which takes the equivalent modulus as a grading constraint and takes band gap quality factor maximization as a target, and performing iterative optimization based on the topological optimization model to obtain an optimal microstructure configuration. According to the invention, efficient and stable design of the microstructure is realized.

The invention provides a method for optimizing a detection sensing material for trace characteristic gas in transformer oil, and belongs to the technical field of detection of gas in transformer oil, and the method comprises the following steps: firstly, obtaining basic data of candidate materials, including material composition, atomic structure, electron energy band structure and theoretical gas sensing performance parameters; and establishing a sensing performance prediction model considering the material composition and structure, and training a material-performance correlation model by using a machine learning algorithm. A large number of theoretical material data sets are generated through computer traversal, and multi-dimensional clustering analysis is performed on candidate materials to obtain a clustering center. And carrying out laboratory performance testing by taking a clustering center corresponding material as a to-be-tested set, and collecting actual performance data. And carrying out multi-generation iterative optimization on the material with the optimal performance by adopting a genetic algorithm to finally obtain the transformer oil trace characteristic gas detection sensing material. The problem that an existing gas sensing material is difficult to meet harsh requirements of an electric power system on online detection of a transformer in the aspects of sensitivity, selectivity and stability is solved.

The invention belongs to the technical field of new materials and electronic information, and particularly relates to a transition metal doped ZnIn2S4 gas sensor as well as a preparation method and application thereof. The gas sensor comprises a substrate and a transition metal doped ZnIn2S4 nano array growing on the surface of the substrate in situ, the nano array is composed of a plurality of two-dimensional nano sheet layers, the two-dimensional nano sheet layers are arranged in a staggered stacking mode and extend at an included angle of + / -5 degrees relative to the normal direction of the surface of the substrate, and the transition metal doped ZnIn2S4 nano array is arranged on the surface of the substrate. And a network assembly with a three-dimensional flower-shaped topological structure is formed through physical or chemical connection. The preparation method is simple, the energy band structure of the material is effectively regulated and controlled, the forbidden band width is reduced, on the other hand, the specific surface area of the material is remarkably increased, and the pore size distribution is optimized. And the prepared gas sensor shows excellent gas selectivity to triethylamine, is high in response value and high in recovery speed, and is expected to be applied to the fields of environmental monitoring and food safety.

The invention discloses a rare bismuth II type superlattice material and a preparation method thereof. The superlattice material has an InAs (Bi) / GaSb or InAs (Bi) / InAsSb superlattice structure formed by alternately laminating InAs (Bi) layers and GaSb layers or InAsSb layers, and the InAs (Bi) layers are formed by introducing Bi elements into the InAs layers. The preparation method of the superlattice material comprises the following steps: (1) selecting an InSb, InAs or GaSb substrate, performing thermal cleaning on the substrate at 500 DEG C, and cleaning the substrate by using atomic hydrogen in an ultrahigh vacuum environment; (2) alternately laminating InAs (Bi) layers and GaSb layers or InAsSb layers by utilizing a molecular beam epitaxial growth technology, and finally growing a GaSb layer or InAsSb layer as a stop layer, (3) carrying out rapid thermal annealing treatment at the temperature of 380-420 DEG C; the time is 0.5 to 1 min; and (4) characterizing the photoluminescence property of the superlattice. According to the invention, the strain distribution and the energy band structure of the material are obviously improved, the more flexible wavelength regulation and control capability is realized, the hole effective quality is reduced, and the carrier mobility and the quantum efficiency are improved.

The invention provides a Se anion-doped ferric phosphate pyrophosphate / carbon positive electrode active material and a preparation method and application thereof, and relates to the technical field of electrochemical energy storage device positive electrode active materials, the positive electrode active material comprises a ferric phosphate pyrophosphate base material and a carbon coating layer, in the crystal structure of the base material, part of O is partially replaced by Se, and the general formula of the base material is Na4Fe3 (PO4) 2 (P2O7-xSex), x is less than or equal to 1.0; o < 2-> is partially replaced by Se < 2-> in a crystal structure of a matrix material to construct a Se-doped solid solution, so that an electron energy band structure of the material is regulated and controlled; due to introduction of Se, the band gap of the material can be remarkably reduced, the electron conductivity can be improved, local lattice distortion can be caused, a Na < + > diffusion channel can be widened, and the ion migration capability can be improved; the material keeps a complete main phase structure, electron and ion transmission is synergistically optimized, and the rate capability is remarkably improved.

The invention provides a nitrogen-vacancy carbon nitride / indium oxide heterojunction photocatalyst as well as a preparation method and application thereof, and belongs to the technical field of photocatalysts. The nitrogen vacancy carbon nitride is used as a framework of the catalyst, and the charge distribution of the carbon nitride can be adjusted by nitrogen vacancy defects, so that the carrier migration rate and the surface active site abundance are improved; the nitrogen vacancy also changes the charge recombination mode of the carbon nitride, the energy band structure of the carbon nitride is beneficially adjusted, the photovoltaic performance of the carbon nitride is improved, the visible light response range of the carbon nitride is widened, and the photocatalytic performance of the carbon nitride is remarkably improved; indium oxide is introduced to form a heterojunction with nitrogen vacancy carbon nitride, so that electron-hole recombination can be inhibited, a new electron transmission channel is generated, and the carrier transmission rate is increased; the band gap characteristic of indium oxide is consistent with the band gap characteristic of nitrogen vacancy carbon nitride, so that the photocurrent response intensity of the catalyst can be improved, the charge transfer resistance is reduced, and the photocatalytic performance is synergistically enhanced.

The invention provides a temperature sensor and a preparation method thereof, and the method comprises the steps: introducing displacement cations into a transition metal nitride film to form a displacement doped transition metal nitride film, the displacement cations being equivalent to transition metal cations; the crystal structure and the energy band structure of the thin film are regulated and controlled by regulating and controlling the concentration of the displacement cations, so that the conductivity of the thin film is regulated and controlled, and the displacement doped transition metal nitride thin film is obtained; and processing the displacement doped transition metal nitride film through an MEMS technology to obtain the temperature sensor. According to the invention, the high-sensitivity temperature zone of the temperature sensor based on the doped transition metal nitride film can be regulated and controlled in a range from low temperature to room temperature, and the temperature range of the high-sensitivity temperature zone of the temperature sensor is widened.

The invention provides a nonlinear ultrasonic detection method and device based on a photonic crystal, and relates to the technical field of nonlinear ultrasonic detection.The photonic crystal structurally comprises rectangular protrusions and a main board, and the upper surface and the lower surface of the main board are each provided with a plurality of identical rectangular protrusions periodically arranged in the transverse direction; primitive cells of the phononic crystal are formed by symmetrically attaching rectangular protrusions to the upper surface and the lower surface of a main board, and the method comprises the steps that the energy band structure of phonons and crystals is calculated through a constructed finite element model of the primitive cells of the phononic crystal, and the passband range and the forbidden band range of the phononic crystal are analyzed; in nonlinear ultrasonic detection of damage of a material, the photonic crystal is attached to the material, propagation of second harmonics generated nonlinearly by a system is prevented through a forbidden band range, and fundamental waves pass through a passband range. Therefore, through the attached photonic crystal, the nonlinear wave of the system is effectively filtered to reduce the influence of nonlinear ultrasonic detection, and the accuracy and sensitivity of the nonlinear ultrasonic detection are improved.

The application provides an infrared absorption material based on doping regulation, a preparation method and an infrared detector. By introducing selenium atoms to replace tellurium atoms in a sodium gallium telluride material, the material is doped according to a doping ratio of 1:4 to 1:2 of atomic weight, the energy band structure and optical properties of the material are regulated, a new infrared absorption material is obtained, and the light absorption performance of the material in the infrared wave band is significantly improved. According to the component characteristics of the infrared absorption material, a specific preparation scheme is provided, the preparation is completed by grinding, secondary melting and annealing treatment of the set principle mass of sodium single substance, gallium single substance, tellurium single substance and selenium single substance, and the band gap and absorption intensity are accurately adjusted, and the symmetry and crystal stability of the material are also considered.

The invention belongs to the technical field of detector preparation, and particularly discloses a preparation method of a B-site cation doped perovskite X-ray detector and a product. Comprising the following steps: respectively preparing a bottom-layer precursor solution SL with low doping concentration of B-site cations and a top-layer precursor solution SH with high doping concentration of B-site cations; firstly blade-coating the bottom-layer precursor solution SL on a base, then blade-coating the top-layer precursor solution SH on the surface of the base in a laminated manner to form a wet mold with a B-site cation longitudinal concentration gradient, and introducing a 2D organic cation solution into the surface of the wet mold to perform an in-situ reaction so as to construct a 2D / 3D perovskite heterostructure; and carrying out segmented annealing crystallization on the wet mold constructed with the 2D / 3D perovskite heterostructure to obtain a compact gradient doped perovskite thick film, and then preparing a metal electrode on the surface of the gradient doped perovskite thick film. According to the invention, doped ions adjust an energy band structure, the effective quality of carriers is reduced, and the mobility is improved, so that the photo-generated current response and the signal-to-noise ratio are improved.

The application relates to a preparation method of a composite semiconductor photocatalyst and application thereof, and comprises the following steps: preparing g-C3N4 nanosheets; dispersing the prepared g-C3N4 nanosheets into methanol at a mass fraction of 10% to 70%, then adding 750 mg of trimesic acid and 150 mg of bismuth nitrate, and ultrasonic treating for 10 min to obtain a mixed suspension; transferring the mixed suspension into a microwave reaction kettle for reaction, the reaction temperature is 90 to 130 DEG C, the reaction time is 30 to 60 min, and centrifugal drying is carried out after the reaction is completed; then g-C3N4 / Bi-MOF is obtained through anhydrous methanol washing and freeze drying; a heterostructure is constructed, the energy band structure is changed, the charge transmission resistance is reduced, the photocatalytic activity is improved, the photocatalyst has two different structure and property photocatalytic activity centers, and the photocatalytic activity is changed from the energy band structure and the catalytic activity.

This invention discloses a copper-tungsten oxide / zinc oxide heterojunction photocatalyst, its preparation method, and its application, belonging to the field of nanomaterials and photocatalysis technology. Firstly, a single-atom copper-modified plasma W-type photocatalyst is synthesized using a solution-thermal method combined with an impregnation-thermal reduction process. 18 O 49 Nanowires were first prepared; then porous ZnO nanosheets were prepared via a hydrothermal method combined with calcination; finally, single-atom copper-modified plasma W was constructed via electrostatic self-assembly. 18 O 49 Nanowire / porous ZnO nanosheet heterojunction composite material. This invention utilizes the above-described preparation method to prepare Cu-W nanowires with matched band structures. 18 O 49 / ZnO heterojunction can realize the photogenerated electrons of ZnO into the plasma Cu-W 18 O 49 Nanowire implantation stabilizes and increases the surface oxygen vacancy concentration and free electron density, thereby enhancing the surface plasmon resonance effect and promoting the continuous generation of high-energy hot electrons. Single-atom copper active sites and W 18 O 49 The synergistic effect of nanowires enables the enriched hot carriers to efficiently and selectively photocatalytically reduce CO2 to CH4.

The invention discloses a fine simulation method of a CdTe-based II-VI group compound thin film solar cell and a cell structure designed based on the method. According to the method, a physical model of a CdTe-based battery is established through numerical simulation, then the energy band structure of a carrier transport layer is systematically optimized, and the quantitative criteria that a hole transport layer needs to meet the requirements that the Fermi energy level is lower than that of an absorption layer and the hole transport layer has enough positive conduction band offset and an electron transport layer needs to have a wide band gap and moderate positive conduction band offset are determined. And for the optical layer, the optimal thickness of the antireflection layer is determined, the enhancement effect of the optical path gain of the textured structure on optical absorption is quantified, and the maximization of the light capture efficiency is realized. According to the method, through electrical-optical coupling simulation, the CdTe-based solar cell structure of which the conversion efficiency is remarkably improved can be accurately predicted and guided to be designed, the defects that a traditional experiment is high in trial and error cost and long in period are effectively overcome, and a reliable theoretical design and optimization tool is provided for research and development of a high-efficiency and low-cost CdTe-based solar cell.

The present disclosure relates to a method and apparatus, equipment, and computer-readable storage medium for adjusting the frequency of a topological state, and relates to the field of engineering structure technology. The method comprises: using a piezoelectric sheet as a resonator, generating a target unit structure through the unit structure of the piezoelectric sheet and the target material; applying periodic boundary conditions to the target unit structure to obtain the band structure of the unit structure and the topological band gap in the band structure; using the target unit structure to generate a one-dimensional target system, setting a displacement excitation to the one-dimensional target system to obtain an excited topological state in the topological band gap; applying a voltage to the one-dimensional target system, and adjusting the excitation frequency of the excited topological state based on the voltage. The present disclosure realizes the control of the excitation frequency of the topological state by an external voltage while keeping the target material structure unchanged, thereby simplifying the operation and improving the flexibility of the system.

The invention relates to the technical field of photocatalysis, in particular to a medium-entropy sulfide photocatalyst and a preparation method and application thereof.Atomic-scale uniform distribution of quaternary metal elements generates a remarkable medium-entropy effect, an energy band structure can be regulated and controlled through a local stress field formed through lattice distortion, and the light absorption edge of a material is expanded; meanwhile, the carrier migration rate is increased through the electron synergistic effect among multiple elements, and photocatalytic reaction kinetics is remarkably enhanced; in addition, the unique particle morphology of the medium-entropy sulfide provides abundant active site exposure and efficient substance transmission channels; compared with traditional sulfides, the structure reduces the recombination rate of photo-induced electron-hole pairs, and effectively improves the photocatalytic activity.

The invention relates to the technical field of semiconductor photoelectric devices, and discloses a GeSe / Si heterojunction photoelectric device and a preparation method thereof, the GeSe / Si heterojunction photoelectric device comprises a bottom electrode, an n-type silicon substrate, a GeSe layer and a top electrode; wherein the n-type silicon substrate and the GeSe layer form a Van der Waals heterojunction, the whole GeSe / Si heterojunction photoelectric device is of a sandwich structure, the bottom electrode is in contact connection with the n-type silicon substrate, and the top electrode is in contact connection with the GeSe layer. The GeSe / Si Van der Waals heterojunction-based high-performance photoelectric device with a sandwich structure and an II-type energy band structure is designed and prepared, due to the light transmission of the Au / ITO top electrode, GeSe with a high light absorption coefficient is used as a light absorption layer, a large number of photon-generated carriers can be generated, and the photoelectric device can be applied to the field of photoelectric devices. A built-in electric field and an II-type energy band structure of the GeSe / Si heterojunction can quickly separate photon-generated carriers to form light current, so that high responsivity of 29.8 A / W, high quantum efficiency of 6959.7% and quick light response time of 8.5 / 23.7 us are realized.

The invention provides a gallium nitride heterojunction ultraviolet detector and a preparation method thereof. The gallium nitride heterojunction ultraviolet detector comprises a first electrode, a substrate, a two-dimensional h-BN layer, a non-doped GaN nucleating layer, a p-type GaN layer and a second electrode which are sequentially stacked. The two-dimensional h-BN layer is inserted to serve as an epitaxial template, so that the preparation process is simplified, the cost is reduced, and high-quality GaN film growth is realized. The two-dimensional h-BN is used as the tunneling layer, the gallium nitride heterojunction photoelectric detector structure is optimized, the atomic-scale thickness and the wide forbidden band energy band structure are utilized, carriers between heterojunctions can efficiently penetrate through the insulating layer through the quantum tunneling effect, an efficient vertical transport path is provided for photo-generated electron hole pairs, and the photoelectric detector efficiency is improved. Meanwhile, the interface passivation effect can effectively inhibit interface scattering and interface recombination, and extremely low dark current is achieved.

The invention relates to the technical field of photoelectric elements, and discloses a laser element with a two-dimensional Moire superlattice layer. Comprising a substrate layer, an n-type coating layer, the two-dimensional Moire superlattice layer, a lower waveguide layer, a quantum well active region, an electron blocking layer, an upper waveguide layer, a p-type coating layer and a p-type contact layer from bottom to top in sequence. The two-dimensional Moire superlattice layer is introduced between the n-type coating layer and the lower waveguide layer, the limiting effect of current carriers can be effectively improved, leakage current is reduced, meanwhile, the superlattice layer has a unique energy band structure, light field distribution of a device is optimized, in addition, by optimizing the structural design and the doping process of the p-type region, the light field distribution of the device is optimized, and the light field distribution of the device is optimized. And the electrical performance of the device can be obviously improved.

The invention discloses a preparation method of a rare earth doped Bi2MoO6 / In2O3 heterojunction composite photocatalyst, and belongs to the technical field of photocatalytic materials, and the preparation method specifically comprises the following steps: S1, preparing a precursor; step S2, preparation of a solid-liquid mixture: putting bismuth salt, rare earth metal salt, hexadecyl trimethyl ammonium bromide and sodium molybdate into deionized water, performing ultrasonic dispersion, adding the precursor In2O3, and performing ultrasonic stirring and uniform mixing to obtain the solid-liquid mixture; and S3, carrying out a hydrothermal reaction on the solid-liquid mixture, naturally cooling, centrifuging, carrying out solid-liquid separation, washing the solid with deionized water, and drying to obtain the rare earth doped Bi2MoO6 / In2O3 heterojunction composite photocatalyst. According to the invention, rare earth doping (especially yttrium Y doping) is introduced, so that the light absorption capacity of the material is further enhanced, efficient migration and compounding inhibition of photo-induced electrons and holes are realized, regulation and control of the energy band structure and light absorption performance of the material are realized, the utilization rate of visible light is further enhanced, and finally, the photocatalytic activity is remarkably improved.

The invention discloses a preparation method of a Z-type heterojunction composite catalyst capable of inducing photon-generated carrier transfer by piezoelectric polarization, multiferroic BiFeO3 and favorable visible light response CdS nanosheets are utilized to construct a Z-type heterostructure with an active electron transmission characteristic, so that the light absorption capacity and an energy band structure are optimized; due to the combination of the BiFeO3 particles and the ultrathin CdS, not only is the agglomeration of the CdS nanosheets inhibited, but also the specific surface area of a reaction system is favorably increased. According to the invention, multiferroic BiFeO3 and a favorable visible light response CdS nanosheet are utilized to construct a Z-type heterostructure with an active electron transmission characteristic. The construction of the active electron transmission system promotes the separation and transmission of current carriers, and provides a new strategy for improving the photocatalytic hydrogen production reaction activity.

The application belongs to the technical field of photocatalysis, and discloses application of peroxymonosulfate assisted g-C3N4 / CoOOH composite photocatalyst in degrading norfloxacin; g-C3N4 is prepared by taking melamine as raw material, then g-C3N4 is added in the preparation of CoOOH to carry out compounding, and g-C3N4 / CoOOH catalyst is prepared by a plurality of hydrothermal methods; g-C3N4 and CoOOH construct heterojunction to improve the electron transfer capacity, have good energy band structure, greatly improve the photocatalytic degradation capacity, and have excellent activation peroxymonosulfate (PMS) capacity, which is used for exciting PMS to generate ·SO4 2‑ , and is used for degrading norfloxacin, has good degradation effect, and has stronger degradation activity.

The invention belongs to the technical field of antibiotic wastewater treatment, and particularly relates to a Z-type CdWO4 / Bi2WO6 catalyst as well as a preparation method and application thereof. The catalyst is formed by loading CdWO4 particles on a Bi2WO6 nanosheet unit. The Z-type CdWO4 / Bi2WO6 catalyst is prepared by adopting a hydrothermal process, the photo-generated charge separation efficiency and the sulfadiazine degradation rate of the catalyst are remarkably improved through energy band structure regulation and interface optimization, and meanwhile, the catalyst has excellent structural stability and recycling performance. The Z-type heterojunction is constructed by accurately controlling integration of CdWO4 and a Bi2WO6 substrate, and the Z-type CdWO4 / Bi2WO6 catalyst is high in light adsorption capacity, high in electron hole separation efficiency, stable in material structure, fast in photon-generated carrier transmission and capable of effectively inhibiting recombination of photon-generated carriers.

The invention discloses a two-dimensional acoustic crystal based on a microstructure. A functional material layer of the two-dimensional acoustic crystal comprises square acoustic cells which are periodically arranged in an xy plane according to a square lattice; a scatterer in the acoustic cell has rotational symmetry and is composed of a cross structure and four identical semicircles, the cross structure is composed of two identical rectangular strips in an orthogonal mode, the diameter of the semicircle is collinear with the short edge of the rectangular strip at the tail end where the semicircle is located, and the diameter of the semicircle is larger than the length of the short edge of the rectangular strip. The rotation angle of the scatterer is matched with the geometric parameter of the scatterer, so that the physical energy band structure of the two-dimensional acoustic crystal generates a triple degeneracy point formed by the first three physical energy bands at the M point of the Brillouin region, and further a stable boundary state with global characteristics is realized. Furthermore, an acoustic frequency beam splitter is constructed on the basis of the boundary state, and sound waves of different frequency bands are split to form included angles of 180 degrees and 90 degrees.

The invention belongs to the technical field of environmental functional materials, and relates to a heterojunction photocatalyst as well as a preparation method and application thereof. The heterojunction photocatalyst is of a Z-type energy band structure and comprises beam-shaped h-BN and Ag3PO4 nano-particles loaded on the beam-shaped h-BN, and the particle size of the Ag3PO4 nano-particles ranges from 1 nm to 20 nm. According to the heterojunction photocatalyst, the initial degradation rate of levofloxacin hydrochloride in visible light within 60 min is larger than or equal to 88%, and the degradation rate is kept to be 80% or above after four times of circulation.

This invention discloses a method and system for screening high-performance layered nitride thermoelectric materials, comprising: obtaining a series of crystal structures of initial layered nitrides; performing magnetic tests on the materials using first-principles calculations to select non-magnetic materials; optimizing the structure of non-magnetic materials, and after calculation convergence, performing static calculations and electronic band structure calculations to select materials with a band gap range of 0.1~3 eV and high band structure degeneracy; calculating the partial charge density of the materials to determine whether there is a two-dimensional electron gas, i.e., alternating conductive and insulating layers; determining stability by performing phonon spectrum and molecular dynamics simulations on the materials to select materials with no imaginary frequencies in the phonon spectrum and stable dynamics; calculating the thermal transport properties of the materials, obtaining the lattice thermal conductivity and Green'sson parameters, and searching for materials with strong anharmonicity; and finally performing electrical transport calculations to obtain the ZT value of the materials.

This invention discloses an electrochromic covalent organic framework material and its application in smart windows, belonging to the technical field of electrochromic functional materials. The material possesses a gradient-tunable band structure and redox potential. The preparation method involves mixing a monomer containing tris(4-aminophenyl)amine with monomers containing linker units with different numbers of nitrogen atoms and an organic solvent, ultrasonically dispersing the mixture, and then adding a catalyst to form a mixture. A cleaned ITO glass is immersed in the mixture. The mixture undergoes cryogenic degassing, followed by in-situ polymerization under heating conditions. After the reaction, the product is washed and dried to obtain an electrochromic COF film. This invention achieves a positive shift in the oxidation potential system and an expansion of the charge delocalization range through the modulation of the electronic structure of the linker units. The material exhibits high optical contrast, fast response, low driving voltage, and good cycling stability.

This invention provides a cathode material, its preparation method, and its application. The cathode material is Li(TM). 1‑a M a )O 2‑b N b (TM represents a transition metal, M represents a cation replacing the transition metal, and N represents an anion replacing oxygen, where 0.01 ≤ a < 1, 0.01 ≤ b < 2). At least one cation and one anion are doped at the interface of the cathode material using a coating-based heat treatment method. Co-doping of cations and anions is achieved at the interface of the cathode material using this method; the doping depth is 10–500 nm. Cation doping stabilizes the material lattice through strong M-O bonds, inhibiting transition metal migration; anion doping reduces oxygen activity and simultaneously adjusts the electronic band structure, improving electronic conductivity. Therefore, Li(TM) 1‑a M a )O 2‑b N b It has a synergistic optimization effect, which not only significantly improves the ion diffusion coefficient and thus optimizes the rate performance, but also improves the cycle stability by enhancing structural stability, thus having great application value and development prospects.