134 results about "Electronic band structure" patented technology

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 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 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 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.

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 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 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.

The invention discloses a method for activating a copper-indium-sulfur thin film through selenium ions at a low temperature and a solar cell based on the thin film. According to the method, the CuInS2 thin film prepared by spin coating is treated by adopting the selenium ion solution, so that diffusion and distribution of selenium ions in the CuInS2 thin film prepared by spin coating are accurately regulated and controlled, carrier recombination is inhibited, and the CuInS2 thin film which is better in energy band structure, lower in defect state density and better in crystallinity and morphology is obtained; and the solar cell with high efficiency (more than 10.0%) is prepared on the basis. The method disclosed by the invention has the advantages of simplicity in operation, low equipment requirement, low cost, low toxicity of used drugs and small damage of a treatment technology to a thin film structure, overcomes the defects of complicated operation, high equipment requirement, damage to a thin film crystal structure by treatment in a high-temperature environment and the like in the prior art, and opens up a new way for high-performance and low-cost inorganic thin film photovoltaics.

The invention belongs to the field of preparation of nano composite materials and application of environmental protection, and discloses a composite material with ZnSe nano particles growing on the surface of a PDI nanosheet, a preparation method and application of the composite material. According to the method, PDI nanosheets are prepared through high-temperature roasting and emulsion polymerization, ZnSe nanoparticles are loaded in situ through a solvothermal method, the Z-type PDI / ZnSe composite photocatalytic material is successfully constructed, and the Z-type PDI / ZnSe composite photocatalytic material is used for photocatalytic preparation of hydrogen peroxide and photocatalytic reduction of hexavalent chromium ions in sewage. Due to the interface Z-type energy band structure, the driving effect of built-in potential significantly inhibits the recombination behavior of photon-generated carriers, so that the strongest oxidation and reduction characteristics of photo-generated electrons and holes are maintained, and the photocatalytic activity is significantly enhanced. The raw materials used in the method are wide in source and easy to obtain, conditions are mild and controllable, repeatability and feasibility are good, and the method has industrial and large-scale application prospects in the aspects of solving water body pollution and synthesizing high-added-value chemicals.

The application belongs to the field of new materials and electronic information technology, and particularly relates to a transition metal doped ZnIn2S4 gas sensor and a preparation method and application thereof. The gas sensor comprises a substrate and a transition metal doped ZnIn2S4 nanoarray in situ grown on the surface of the substrate, the nanoarray is composed of a plurality of two-dimensional nanosheet layers, the two-dimensional nanosheet layers are arranged in an interlaced stacking mode and extend at an angle of ±5° relative to the normal direction of the substrate surface, and the two-dimensional nanosheet layers are combined into a network assembly with a three-dimensional flower-like topological structure through physical or chemical connection. The preparation method is simple, the energy band structure of the material is effectively controlled and the band gap is reduced, on the other hand, the specific surface area of the material is significantly increased and the pore size distribution is optimized. The gas sensor prepared by the method has excellent gas selectivity to triethylamine, high response value and fast recovery speed, and is expected to be applied to the fields of environmental monitoring and food safety.

The invention provides a continuous domain bound state merging method and a phase change material metasurface structure, and relates to the technical field of micro-nano optics. The continuous domain bound state merging method comprises the steps of obtaining an energy band structure of a phase change material metasurface structure; determining an energy band simultaneously having a symmetric protection continuous domain bound state and an accidental continuous domain bound state from the energy band structure; based on the energy band, far-field polarization of the phase-change material in the phase-change material metasurface structure in an amorphous state and a crystalline state is calculated, and a corresponding momentum space far-field polarization vector diagram is generated based on the far-field polarization; and according to the momentum space far-field polarization vector diagram, the phase change material is controlled to be converted from the amorphous state to the crystalline state, so that the symmetric protection continuous domain bound state and the accidental continuous domain bound state are combined.

This invention provides a simulation method and application based on the slip ferroelectricity and piezoelectricity of two-dimensional heterolayer materials. The simulation method first constructs a g-C3N4 / graphene heterolayer model, forming various stacking configurations such as AA, AB, and BA. Then, based on density functional theory, structural optimization and electronic structure calculations are performed on the constructed heterolayer model. Based on this, the out-of-plane ferroelectric polarization and in-plane piezoelectric coefficient of the heterolayer under different stacking configurations are solved. Finally, combined with charge transfer characteristics and band structure analysis, the microscopic physical mechanism of the coexistence of slip ferroelectricity and piezoelectric properties of the system is elucidated. This invention can provide a theoretical basis for multifunctional two-dimensional materials through this simulation method, and has broad prospects for applications in memory, sensors, and actuators.

The invention belongs to the technical field of thermoelectric material preparation, and particularly relates to an n-type room-temperature thermoelectric material and a preparation method thereof. And the thermoelectric material is Bi < 2 > Te < 2 > Se + 0.01 wt% BiI < 3 >. The doped thermoelectric material Bi2Te2Se + 0.01 wt% BiI3 is prepared for the first time, the energy band structure is adjusted through doping optimization, the Seebeck coefficient is effectively improved, meanwhile, the heat conductivity is greatly reduced, collaborative optimization of electrical performance and thermal performance is achieved, and the thermoelectric performance of the material is improved; bi2Te2Se is subjected to doping optimization, so that the thermoelectric figure of merit ZT of a sample (Bi2Te2Se + 0.01 wt% BiI3) of the material can reach 0.86 under 300 K; the temperature can reach about 1.17 at 423 K, so that the material is expected to become a new room-temperature commercial thermoelectric material and is expected to become a new commercial thermoelectric material.

The invention relates to a high-voltage-resistant anti-breakdown automobile wire sheath and a preparation method thereof, and relates to the technical field of automobile wire harnesses, and the high-voltage-resistant anti-breakdown automobile wire sheath comprises a modified styrene-ethylene-butylene-styrene block copolymer, polypropylene, functionalized magnesium hydroxide, melamine polyphosphate, white oil and a functional auxiliary agent. An N-vinylcarbazole group grafted on a styrene-ethylene-butylene-styrene block copolymer molecular chain is used as an electron donor, an anthraquinone derivative chemically bonded on the surface of a magnesium hydroxide particle is used as an electron acceptor, and the N-vinylcarbazole group and the anthraquinone derivative form a large number of charge transfer complexes at an interface through pi-pi interaction. According to the charge transfer complexes, a high-density deep energy level trap is introduced into an energy band structure of the material, so that the charge behavior of the material in a high electric field is changed, and high-performance high-voltage-resistant and anti-breakdown effects are realized.

The application relates to a preparation method and application of a hydrophobic hollow double-shell Mo2N-Co3O4@Fe2O3 Z-type heterojunction photoelectrocatalyst, and belongs to the technical field of high-value chemical products and catalyst production. 24 The ZIF-67@Mo-CoFe PBA cube is obtained by reacting Co(NO3)2.6H2O, cetyltrimethylammonium bromide and 2-methylimidazole, then adding K3[Fe(CN)6] to react, and then adding (NH4)6Mo7O The Mo2N-Co3O4@Fe2O3 / PVDF hydrophobic electrode prepared from the Mo2N-Co3O4@Fe2O3 cube can be used for photoelectrocatalytic preparation of H2O2. The application has the characteristics of simplicity, high efficiency, low cost and high absorption in the full spectral range. The prepared hydrophobic hollow double-shell Mo2N-Co3O4@Fe2O3 Z-type heterojunction photoelectrocatalyst has the advantages of large specific surface area, suitable energy band structure, high catalytic activity and stability, good hydrophobicity, high separation efficiency of photo-generated electron-hole pairs, fast interface charge transport efficiency, high H2O2 production in photoelectrocatalytic preparation, and can be applied to the fields of photoelectrocatalytic preparation of H2O2 and degradation of organic matters.

This invention relates to a self-gated resistive switching memory (SRAM). By using niobium oxide, which is less prone to oxygen vacancy accumulation, as the storage layer, the on-state current density is improved. At the same time, by setting a titanium oxide layer with a peak-shaped band structure as the gating layer, the nonlinearity of the device is improved. Thus, the self-gated resistive switching memory has both high nonlinearity and high on-state current density, solving the problem that high nonlinearity and high on-state current density cannot be achieved simultaneously in the prior art.

The application discloses an electron beam irradiation modified active metal loaded covalent organic framework material and a preparation method and application thereof, and belongs to the technical field of environmental science and material science. The application first prepares a metalized COF material, namely M-COF (wherein, M=Co, Ni or Cu; COF is Btt-Bpy-COF) material through a post-modification method, and innovatively introduces an electron beam irradiation modification method on the basis, and successfully constructs a series of eM-COF materials. In the constructed eM-COF, the metal active sites are stably anchored on the COF skeleton, and meanwhile, the energy band structure and charge separation efficiency of the material are optimized, so that the material can be used as a high-efficiency photocatalyst for CO2 reduction. Compared with the M-COF material, the eM-COF material significantly improves the photocatalytic CO2 reduction efficiency, and effectively inhibits the hydrogen evolution side reaction in the aqueous system. The application effectively breaks through the technical bottleneck of the current COF-based photocatalyst in the core performance indexes such as active site regulation, electronic structure optimization and selective CO2 reduction.

The application discloses a gas recognition visual-olfactory fusion optoelectronic synapse device and a preparation method thereof, and belongs to the technical field of semiconductor devices. The optoelectronic synapse device comprises a substrate, a two-dimensional material floating gate heterojunction and source and drain electrodes. The heterojunction at least comprises a channel layer and a floating gate layer stacked thereon, and forms a Type-II energy band structure, and the interface has a defect state for carrier capture and release. The channel layer generates photo-generated carriers in response to light pulses, and the floating gate layer responds to gas stimulation and changes the charge state through gas adsorption / desorption; by applying a programmable light pulse stimulus to the channel layer, the adsorption or desorption process of gas molecules on the floating gate layer and the charge state thereof are dynamically modulated, a dynamic electrical response signal fusing visual and olfactory information is output, and gas recognition is realized. The application significantly improves the gas recognition accuracy from 52.24% of a single mode to 98.27% by using a dual-mode fusion feature, and realizes the synergy of miniaturization, low power consumption and high-precision perception.