30 results about "Cesium bromide" patented technology

The invention discloses a preparation method of a portable paper-based ratiometric fluorescence sensor APBA-CsPbBr3 at-UiO-66 / Ru, which comprises the following steps: 1, adding lead bromide and cesium bromide into N, N-dimethylformamide, then adding 5-bromovaleric acid and an oleylamine ligand, and stirring; 2, perfluorooctyltriethoxysilane is added, and a precursor solution is obtained; 3, adding zirconium chloride and terephthalic acid into N, N-dimethylformamide to obtain a homogeneous solution; 4, after heating, UiO-66 is obtained; 5, stirring the precursor solution, APBA, UiO-66 and tris (2, 2-dipyridyl) ruthenium chloride hexahydrate to obtain a composite material; and 6, dropwise adding the composite material solution into the filter paper. The APBA modified material is adopted as a recognition unit, the APBA modified material and the paper base construct a fluorescence sensing platform, visual quantitative analysis of oxytetracycline in water is achieved, and the device is convenient to carry, low in detection limit, high in anti-interference performance, easy and convenient to operate and suitable for on-site rapid detection of oxytetracycline.

The invention discloses a preparation method and application of high-fluorescence quantum yield perovskite fluorescent powder based on amino acid, and belongs to the technical field of luminescent materials and display, the preparation method is used for preparing the perovskite fluorescent powder, and the preparation method comprises the following steps: dissolving potassium bromide in deionized water, then adding lead bromide, and carrying out ultrasonic dissolution to obtain a first solution; dissolving cesium bromide in another deionized water to obtain a second solution; mixing the first solution and the second solution, and standing to obtain a mixed solution; dropwise adding the mixed solution into absolute ethyl alcohol, and stirring to obtain a precursor solution; adding amino acid into the precursor solution, and stirring to obtain a precursor reaction suspension; and centrifuging the suspension, collecting the precipitate, centrifugally washing the precipitate with absolute ethyl alcohol, and drying the washed precipitate to obtain the perovskite fluorescent powder. The invention provides a green synthesis method of a water-ethanol system, which is combined with an amino acid synergistic passivation effect to realize low-cost preparation and improvement of luminous efficiency.

This invention provides a microgap suspension device and a microgap inverted suspension heat treatment process, comprising the following steps: adding p-aminobenzenesulfonic acid to a solvent, mixing thoroughly, and then adding carbon nanotubes to obtain a carbon nanotube dispersion; stirring the carbon nanotube dispersion under heating conditions to obtain a p-aminobenzenesulfonic acid-modified carbon nanotube dispersion; coating a substrate surface with a lead bromide solution, then coating the lead bromide surface with a cesium bromide solution, then coating the cesium bromide surface with the p-aminobenzenesulfonic acid-modified carbon nanotube dispersion; and finally performing heat treatment through a microgap suspension device to form a photoactive layer film. The microgap inverted suspension heat treatment process of this invention, through controllable height suspension heat treatment, ensures that the film is almost unconstrained by the rigidity of the substrate during thermal expansion and cooling contraction, thus making it suitable for flexible substrates as well. It also avoids direct contact damage to flexible substrates during high-temperature heat treatment.

The invention provides a cesium lead bromide quantum dot / single-layer molybdenum disulfide 0D / 2D heterojunction photoelectric sensor and a preparation method thereof, and belongs to the technical field of photoelectric devices. Constructing a patterned bottom electrode by adopting an Au / p + type silicon substrate / SiO2 structure; preparing a single-layer molybdenum disulfide (MoS2) film by a mechanical stripping method, and transferring the single-layer molybdenum disulfide (MoS2) film to the patterned silicon wafer electrode; and spin-coating the single-layer molybdenum disulfide film with the quantum dot solution, drying and annealing to obtain the cesium lead bromide quantum dot / single-layer molybdenum disulfide 0D / 2D heterojunction photoelectric sensor. According to the invention, CsPbBr3 QDs with efficient light absorption and single-layer MoS2 with high carrier mobility are integrated together, and CsPbBr3 QDs are used as an effective light absorbent to enhance a local electric field around MoS2. And by utilizing the synergistic effect of the CsPbBr3 QDs and the single-layer MoS2, the separation rate of photon-generated carriers in the heterojunction is accelerated, and the light absorption capability of the MoS2 device is improved. The p + type silicon substrate is combined with the annealing process, a Br-rich passivation ultra-clean II type heterojunction interface is constructed, and the charge separation efficiency and the environmental stability are remarkably improved.

The application relates to a large-size orthorhombic phase bromine lead cesium single crystal and a solution growth method and application thereof, and belongs to the technical field of crystal materials. The application comprises the following steps: (1) mixing water and dimethyl sulfoxide uniformly, adding cesium bromide and lead bromide to obtain a bromine lead cesium solution; (2) overheating the bromine lead cesium solution at 70-80 DEG C for 24-48h to obtain a bromine lead cesium growth solution; and (3) growing the bromine lead cesium seed in the bromine lead cesium growth solution or spontaneously nucleating and growing under a sealed condition to obtain a large-size orthorhombic phase bromine lead cesium single crystal. The application uses a mixed solution of water and dimethyl sulfoxide as a solvent of cesium bromide and lead bromide for the first time, lets water participate in the growth of the bromine lead cesium crystal, changes the inverse temperature crystallization property of the CsPbBr3 crystal, changes the solubility of the CsPbBr3 crystal from an inverse temperature curve into a positive temperature curve, realizes the temperature-reducing controlled growth of the crystal, and effectively avoids the generation of other by-products of the bromine lead cesium.

The present application relates to a kind of for CO2 reduction CsPbBr3 quantum dot / BiOCl heterojunction photocatalyst and its preparation method, the preparation method has the following steps: with bismuth oxychloride and lead nitrate is added to aqueous solution, freeze-drying after ultrasonic, by muffle furnace calcination, obtain precursor material;CsPbBr3 quantum dot / BiOCl heterojunction photocatalyst is obtained by two-step calcination method again by adding cesium bromide and potassium bromide, dissolving, ultrasonic, freeze-drying, by muffle furnace calcination its feature is.CsPbBr3 quantum dot / BiOCl heterojunction photocatalyst prepared has excellent performance and good cycle stability.The drug used in preparation is easily obtained and low in price, and preparation is simple and short in time.CsPbBr3 quantum dot / BiOCl heterojunction photocatalyst prepared can be successfully applied in the field of photocatalytic CO2 reduction.

The application discloses a 3D-printable all-inorganic perovskite flexible light-emitting gel and a preparation method and application thereof, and relates to the technical field of perovskite. The method comprises the following steps: dissolving cesium bromide in water to obtain a cesium bromide aqueous solution; adding photo-curing precursor components into the cesium bromide aqueous solution in a certain proportion, and stirring uniformly to obtain a photo-curing precursor mixed solution; obtaining a photo-curing composite hydrogel; obtaining a flexible high polymer gel containing cesium bromide; and performing a spontaneous crystallization reaction, and then performing heat treatment on the gel to remove residual solvents. The perovskite precursors with large solubility difference are introduced into the photo-curing base material in two steps, respectively, so that the compatibility problem of the perovskite and the flexible base material precursor is solved.

The application relates to a preparation method and application of a core-shell structure tin-based perovskite nanocrystal. The application adjusts the feeding ratio of a cesium source and a stannous source and the proportion of oleylamine and oleic acid, and through one-step hot injection, obtains a nanocrystal with a cesium bromide shell and a tin-based perovskite core; and further, a light emitting diode device is prepared by using the nanocrystal. The tin-based perovskite nanocrystal has a sustained and stable high fluorescence quantum yield, and the light emitting diode device prepared based on the nanocrystal has a very high light emitting efficiency.

The invention relates to an improved synthesis process of a cesium germanium bromide halogen perovskite material. The improved synthesis process comprises the following reaction steps: (1) constructing a condensation reflux device and a nitrogen pipeline; (2) weighing germanium dioxide, hydrobromic acid, concentrated hypophosphorous acid and absolute ethyl alcohol; (3) putting the three-neck flask into an oil bath pan, and connecting a condensation reflux device and a nitrogen gas path; (4) after germanium dioxide is completely dissolved, the solution in the flask is clarified; (5) injecting the cesium bromide solution into the three-neck flask in a nitrogen environment, heating, and reacting for a period of time; (6) cooling the solution to room temperature in a nitrogen environment, and collecting a yellow cesium germanium bromide crude product; and (8) refining the crude cesium germanium bromide to obtain refined cesium germanium bromide, wherein the impurity content is lower than 0.5%. According to the method, the cesium-germanium bromide solution and methylbenzene are used, so that the problem that divalent germanium ions and cesium bromide are not completely reacted is solved, and a good solution is provided for synthesizing a high-purity cesium-germanium bromide material.

The invention relates to the technical field of metal halide luminescent materials, and discloses a preparation method of a cesium-lead-bromine-chlorine blue-light quantum dot colloid and a preparation method of a blue-light film. The method comprises the following steps: dissolving cesium bromide and lead bromide in N, N-dimethylformamide, adding oleic acid and oleylamine to form a precursor solution, and injecting the precursor solution into a toluene anti-solvent to prepare CsPbBr3 quantum dot colloid; and then dropwise adding a toluene saturated solution of alkaline earth metal chloride (calcium chloride, strontium chloride, barium chloride or magnesium chloride) for post-treatment to realize ion exchange of Cl <-> and Br <-> and synergistic defect passivation, so that the emission peak is continuously adjustable in the range of 450-500 nm, the half-peak width is less than 30 nm, and the photoluminescence quantum yield is greater than 60%. And further mixing the quantum dot colloid with a polymethyl methacrylate toluene solution and forming a film to obtain a stable blue light quantum dot film which can be used for a backlight source or a display device.

This invention discloses a high-fluorescence quantum yield all-inorganic perovskite thin film, its preparation method, and its applications, belonging to the field of lead-free perovskite optoelectronic device technology. The thin film preparation method includes the following steps: dissolving tin dibromide and cesium bromide in an organic solvent to obtain a precursor solution; adding N-(diphenylphosphino)-P,P-diphenylphosphineamide; coating the obtained perovskite precursor solution onto a substrate; and then annealing to obtain a high-fluorescence quantum yield all-inorganic perovskite thin film, which is a CsSnBr3 perovskite thin film. The CsSnBr3 perovskite thin film prepared using the method of this invention exhibits a high fluorescence quantum yield and improved film coverage. The high-fluorescence quantum yield CsSnBr3 perovskite thin film prepared by this invention can be applied to perovskite light-emitting devices, perovskite solar cells, perovskite photodetectors, and other fields.

The application discloses a cesium copper bromide-silver bromide heterojunction photocatalyst and a preparation method and application thereof, and belongs to the technical field of photocatalytic material for preventing and treating air pollution. The preparation method comprises the following steps: dissolving cesium bromide and copper bromide in dimethyl sulfoxide, and obtaining cesium copper bromide by using an anti-solvent recrystallization method; dispersing the cesium copper bromide into an isopropyl alcohol solution, adding a silver nitrate-isopropyl alcohol solution, sealing the obtained mixed solution, continuously stirring under light irradiation, and obtaining the cesium copper bromide-silver bromide heterojunction photocatalyst through centrifugation, washing and drying. The cesium copper bromide-silver bromide heterojunction photocatalyst provided by the application has stronger photocatalytic reduction capacity, and can greatly improve the activity of the cesium copper bromide-silver bromide in photocatalytic reduction of carbon dioxide.

The invention relates to the technical field of nano material preparation, and discloses formamidine acetate doped CsPbBr3 perovskite nanocrystals and a water phase preparation method thereof.The method comprises the steps that firstly, lead bromide, cesium bromide, formamidine acetate and dimethylacetamide are mixed, and a uniformly-doped precursor solution containing formamidine acetate is prepared under the ultrasonic concussion condition; sequentially adding oleylamine and 5-bromovaleric acid into the precursor solution according to a specific sequence, and carrying out ultrasonic-assisted in-situ surface ligand modification; and finally, rapidly injecting the precursor solution into deionized water, inducing crystallization by using the polarity difference of the solvent, centrifuging to remove the precipitate, and taking the supernatant to obtain the target product. According to the preparation method disclosed by the invention, the structural stability of the CsPbBr3 nanocrystal is remarkably improved through doping of formamidine acetate (FA) to a lattice A site and synergistic coordination of acetate. The obtained nanocrystal has a cubic crystal phase structure and can be stably dispersed in a water phase system, and the technical problem that a traditional perovskite material is easy to decompose when meeting water is solved.

This invention provides a co-encapsulation method for highly stable perovskite quantum dots, comprising the following preparation steps: S1, mixing and grinding a low-crystallinity all-silica zeolite carrier, cesium bromide, and lead bromide to obtain a precursor mixture; S2, heating the precursor mixture to allow the cesium, lead, and halogen components to enter the pores of the low-crystallinity all-silica zeolite carrier, and crystallizing under the confinement of the pores to form CsPbBr3 perovskite quantum dots; S3, contacting the product obtained in step S2 with an aqueous potassium chloride solution and performing hydrothermal treatment to obtain zeolite-encapsulated CsPbBr3 perovskite quantum dots containing lead hydroxide chloride. This invention can reduce the adverse effects of chlorine sources on direct halogen exchange in the perovskite quantum dot bulk lattice and promote the participation of chlorine sources in the formation of a stable protective structure at the carrier interface, thereby improving the stability of perovskite quantum dots.

The invention discloses a porous gallium nitride / cesium lead bromide heterojunction and a preparation method and application thereof, and belongs to the technical field of semiconductors. A sapphire substrate and a magnesium-doped p-type GaN sheet are adopted, and a high-temperature annealing technology is utilized to prepare a porous GaN structure, so that the specific surface area and porosity of a GaN material are increased, the surface wettability of GaN is improved, a solution can form a film more conveniently, and an ideal physical support is provided for permeation and deposition of a CsPbBr3 precursor solution. PbBr2 and CsBr solutions are spin-coated on the surface of the porous GaN through a multi-step method, pores of the porous GaN can be filled with the solutions, a CsPbBr3 thin film is formed after annealing, and finally construction of a three-dimensional heterojunction in the pores is achieved. The heterojunction can effectively separate photon-generated carriers and improve the photoelectric conversion efficiency; the carrier transmission efficiency and collection efficiency are improved, and the carrier transmission path is improved; and the response range of ultraviolet light is widened.

The invention provides a preparation method of zinc-doped perovskite quantum dots and application of the zinc-doped perovskite quantum dots in a photovoltaic film. The preparation method of the Zn-PQD comprises the following steps: dissolving cesium bromide, lead bromide and a zinc dopant in N, N-dimethylformamide, adding oleic acid and oleylamine, and stirring until the materials are completely dissolved to obtain a precursor solution; ethyl acetate is added into the precursor solution, and Zn-PQD is formed. The energy band gap of the PQD is regulated and controlled by doping Zn, visible light absorption is increased, the photon transition rate is increased, and the fluorescence efficiency and stability of the PQD are improved. According to the Zn-doped CsPbBr3 quantum dots, Pb is partially replaced by Zn, perovskite crystal lattices are gradually shrunk, a transition energy band is reduced, and the fluorescence efficiency is greatly improved. And the Zn-PQD / EVA film is obtained through compounding with the EVA, so that the stability of the Zn-PQD is improved, the light transmittance of the EVA is improved by improving light absorption, and the photoelectric conversion efficiency of the solar cell is improved.

The invention discloses preparation of a bright and stable CsPbBr3-coated MS-Al composite material and application of a pore channel microenvironment regulation and control strategy to a light emitting diode, and the preparation method comprises the following steps: 1, taking deionized water, hydrochloric acid, Pluronic P123 and tetraethyl orthosilicate (TEOS) as raw materials, and obtaining a mesoporous molecular sieve MS through a hydrothermal method; 2, sodium metaaluminate (NaAlO2) is used as a modifier, and the mesoporous molecular sieve MS-Al is obtained through a post-modification impregnation method. And 3, taking cesium bromide (CsBr), lead bromide (PbBr2) and the mesoporous molecular sieve MS-Al as raw materials, and preparing a product CsPbBr3-coated MS-Al through solid-phase grinding and high-temperature calcination methods. By forming a mesoporous coating structure, the CsPbBr3 quantum dots are uniformly distributed in MS-Al pore channels, and the luminescence property and stability of the material are effectively improved. The prepared CsPbBr3-coated MS-Al composite material has the photoluminescence quantum yield of 81%, and meanwhile has the excellent anti-interference capability on environmental factors. The luminance of a light-emitting diode (LED) prepared from the light-emitting layer is still 90% of that of an initial state when the LED continuously works for more than 600 hours under the working current of 23 mA and the operating voltage of 3.11 V.

The invention relates to a metal organic gel type composite adsorbent as well as a preparation method and application thereof. The metal organic gel type composite adsorbent comprises metal organic gel and hygroscopic salt, the hygroscopic salt comprises any one or a combination of at least two of calcium chloride, magnesium chloride, sodium chloride, barium chloride, cesium chloride, lithium bromide, calcium bromide, magnesium bromide, sodium bromide, barium bromide or cesium bromide. According to the preparation method of the metal organic gel type composite adsorbent, synthesis conditions are mild, large-scale preparation is easy, a reaction product is blocky gel, a final product is a granular integral adsorbent after drying, the adsorbent has efficient water vapor adsorption capacity, and the adsorbent has good application prospects. The metal organic gel type composite adsorbent has excellent adsorption and desorption performance and good cycle stability on water vapor.

The invention discloses a preparation method of a one-dimensional cesium-lead-bromine nanowire film, a film material, an element and equipment. The preparation method comprises the following steps: preparing a first solution containing a proper amount of acetone, toluene and a surfactant; weighing lead bromide and cesium bromide in a molar ratio of 1: 1, and grinding into uniform powder; in a constant-temperature water bath, adding the powder into the first solution, and stirring for reaction; after the reaction is finished, separating and washing to obtain a pure cesium-lead-bromine nanowire; dispersing the cesium-lead-bromine nanowires in a mixed solvent of normal octane and normal hexane to obtain a nanowire dispersion liquid required for preparing the thin film; and coating the nanowire dispersion liquid on a substrate, and drying at room temperature to obtain the uniform one-dimensional cesium-lead-bromine nanowire film with high polarization luminescence and polarization response. According to the invention, the preparation process of the one-dimensional cesium-lead-bromine nanowire film is optimized, and the preparation of the macroscopic orientation cesium-lead-bromine nanowire film with high polarization luminescence and polarization response is realized, so that the preparation of an optical device with good anisotropy and polarization performance is realized.

The application relates to a synthesis method of AB co-doped manganese ion halide nanomaterials, which comprises the following steps: 1) mixing raw materials such as cesium bromide, A-site dopant raw materials and B-site dopant raw materials, carrying out surface activation treatment after mixing, and then carrying out high-energy ball milling to obtain a mixture; 2) adding the mixture into a mixed solution of a reaction solvent and a ligand, and carrying out reaction under the assistance of ultraviolet light to realize ligand passivation, so as to obtain a reaction product; 3) carrying out silica coating on the reaction product to obtain superparamagnetic particles; and 4) carrying out drying, ball milling and static electricity elimination treatment on the superparamagnetic particles to obtain AB co-doped manganese ion halide nanomaterials. The application synthesizes AB co-doped manganese ion metal halides with high purity by adopting a solid-phase method, and the luminous intensity is improved compared with common manganese ion metal halide nanomaterials.

The application belongs to the technical field of solar cells, and provides a preparation method of inorganic perovskite nanowire film. First, lead iodide is dissolved and stirred uniformly under constant temperature to obtain a lead iodide precursor solution; a precipitating agent is added to the lead iodide precursor solution to obtain light yellow flocculation, and the light yellow flocculation is centrifuged to obtain light yellow colloidal material, which is vacuum dried to obtain a lead iodide composite product; a precursor spin coating solution is obtained based on the lead iodide composite product, the precursor spin coating solution is spin coated on a substrate to form a film, and annealing treatment is performed to obtain a loose lead iodide film layer; the lead iodide film layer is sequentially immersed in a cesium iodide solution and a cesium bromide solution, and then annealing treatment is performed to obtain an inorganic perovskite film, so that the loose PbI2 nanostructure can fully contact and react with the cesium iodide solution and the cesium bromide solution, and a one-dimensional inorganic perovskite nanowire material with good orientation, excellent physical and chemical stability and high crystallinity is prepared.

The application relates to the technical field of perovskite materials, and discloses a perovskite light-emitting diode based on ferrocene formic acid modification and a preparation method thereof, the preparation method comprises the following steps: repeatedly cleaning an ITO substrate with deionized water, ethanol and dichloro, and then cleaning the substrate by using an ultraviolet ozone machine; depositing a PEDOT:PSS solution on the surface of the substrate obtained in step 1 in a rotary coating mode, and then performing annealing treatment; dissolving ferrocene formic acid into chlorobenzene, stirring the solution until the solution is dissolved to obtain a mixed solution, depositing the mixed solution on the surface of the substrate obtained in step 2 in a rotary coating mode, and then performing annealing treatment; and dissolving lead bromide, cesium bromide, phenethylammonium bromide and crown ether into a mixed solution of DMSO and PVP. The quasi-two-dimensional perovskite thin film prepared by the application has high light-emitting color purity and high quantum efficiency, and the prepared perovskite light-emitting device has high light-emitting performance and high stability.

This invention discloses a method for preparing a blue light-emitting thin film, the blue light-emitting thin film, and a light-emitting device. The method involves dissolving a mixture of cesium bromide, lead bromide, lead chloride, and an organic ligand in dimethyl sulfoxide solvent to obtain a precursor solution. An additional ligand is added to the precursor solution to obtain a perovskite precursor solution. An additive is added to the perovskite precursor solution, and the mixture is stirred for a predetermined first time to obtain a homogeneous solution. The homogeneous solution is then spin-coated in a nitrogen-filled glove box, with an antisolvent added during the spin-coating process to obtain a raw thin film. The raw thin film is annealed and then vacuum-dried to obtain a blue light-emitting perovskite thin film. The above method uses amine salts as organic ligands and small-molecule amine salts as additional ligands, ultimately resulting in a significant improvement in the photoluminescence quantum efficiency, maximum external quantum efficiency, and maximum power efficiency of the prepared blue light-emitting perovskite thin film, as well as achieving high maximum brightness and a stable electroluminescence spectrum.

The invention relates to chiral perovskite and a preparation method thereof.The method comprises the steps that formamidine bromide, cesium bromide and lead bromide are mixed and added into an organic solvent, a three-dimensional perovskite precursor solution is obtained, and the organic solvent is formed by mixing N, N-dimethylformamide and dimethyl sulfoxide; spin-coating the three-dimensional perovskite precursor solution on a quartz substrate to form a three-dimensional perovskite thin film; before spin coating is finished, an anti-solvent containing chiral R / S-1-(1-naphthyl) ethylamine hydrobromide is dropwise added to the surface of the three-dimensional perovskite thin film for in-situ reaction, then annealing treatment is carried out, and the chiral perovskite is obtained. The chiral perovskite provided by the invention is prepared by combining achiral three-dimensional perovskite and chiral two-dimensional perovskite, and the chiral perovskite is actually a two-dimensional / three-dimensional heterojunction film, so that the optical activity of the chiral two-dimensional perovskite can be greatly enhanced; the method has a wide prospect in the aspect of preparing a small, flexible and highly integrated circularly polarized light detector.

The invention provides a modified perovskite light absorption layer and a preparation method and application thereof, and the preparation method comprises the following steps: (1) carrying out the one-step evaporation treatment on the surface of a substrate through lead iodide, cesium bromide and lead chloride, and obtaining a first evaporation layer; (2) carrying out two-step evaporation treatment on the surface of the first evaporation layer by using lead iodide, cesium bromide and lead chloride to obtain a second evaporation layer; and (3) carrying out three-step evaporation treatment on the surface of the second evaporation layer by using organic cation amine salt to obtain an organic cation amine salt layer, and carrying out annealing treatment on the obtained material to obtain the modified perovskite light absorption layer, wherein the evaporation rate of the one-step evaporation treatment of lead chloride is gt; the evaporation rate of the two-step evaporation treatment of lead chloride is increased. According to the method for preparing the modified perovskite light absorption layer, the compactness of the thin film can be adjusted, the high perovskite phase conversion degree is promoted, and the quality of the perovskite light absorption layer is improved.

The application discloses a preparation method of a complex-phase CsBr / Cs3Bi2Br3I6 array film and application thereof, and relates to the technical field of semiconductors.The specific process of the application is as follows: CsBr microspheres are deposited on the surface of interdigital electrodes by a simple gas phase evaporation method of cesium bromide, bismuth iodide is used as a reaction raw material, N,N-dimethylformamide is used as a solvent, and a Cs3Bi2Br3I6 array film is in-situ reaction-grown on the CsBr microspheres by multiple spraying and heat treatment, the film is uniform and porous, Cs3Bi2Br3I6 sheet-shaped nanocrystals are vertically grown on the surface and gaps of the CsBr microspheres, the diameter of the CsBr microspheres is 1-3 microns, the thickness of the Cs3Bi2Br3I6 nanosheet is 50-100 nanometers, the film is firmly combined with a base material, and the prepared complex-phase CsBr / Cs3Bi2Br3I6 array film shows room-temperature sensitive performance to hydrogen sulfide gas.Compared with the prior art, the application has the advantages of reasonable preparation process design, high uniformity of large-area film formation, strong operability, high sensitivity to H2S gas at room temperature, and good long-term stability.

The invention relates to an optical binary encryption method based on metal halide perovskite, which comprises the following steps: reacting cesium bromide with lead bromide to generate three-dimensional CsPbBr3 so as to realize the conversion of fluorescence from zero to zero; when cesium bromide is excessive, zero-dimensional Cs4PbBr6 is obtained and shows green fluorescence, and due to instability of the crystal structure, the fluorescence can be converted from existence to absence; after hydrobromic acid is added, zero-dimensional metal halide perovskite Cs4PbBr6 with a stable structure is generated, and fluorescence is converted from existence to existence; under the conditions of hydrobromic acid and polyacrylamide, amido bonds can be coordinated with Pb < 2 + >, so that the growth kinetics of Cs4PbBr6 is regulated and controlled, and the breakthrough of fluorescence from zero to existence is realized. And finally, a binary algorithm is used as an encryption strategy, time gating is used as a decoding key, the three-dimensional CsPbBr3 and zero-dimensional Cs4PbBr6 light emitting conditions are used as optical signals, the optical signals at specific time are converted into binary codes, and information anti-counterfeiting and information encryption can be achieved after decryption is conducted through the binary encryption algorithm.

The invention discloses a cesium copper bromide-silver bromide heterojunction photocatalyst as well as a preparation method and application thereof, and belongs to the technical field of air pollution prevention and control of photocatalytic materials. The preparation method comprises the following steps: dissolving cesium bromide and copper bromide in dimethyl sulfoxide, and obtaining cesium copper bromide by using an anti-solvent recrystallization method; the preparation method comprises the following steps: dispersing cesium, copper and bromine into an isopropanol solution, adding a silver nitrate-isopropanol solution, sealing the obtained mixed solution, continuously stirring under the condition of illumination, centrifuging, washing and drying to obtain the cesium, copper and bromine-silver bromide heterojunction photocatalyst. The cesium-copper-bromine-silver bromide heterojunction photocatalyst provided by the invention has stronger photocatalytic reduction capability, and the activity of the cesium-copper-bromine-silver bromide for photocatalytic reduction of carbon dioxide can be greatly improved.

The application belongs to the technical field of photocatalytic materials, and particularly relates to a hexabismuth bismuth silver acid dicyesium / metal organic framework MIL-53Fe heterojunction photocatalyst and a preparation method and application thereof. The preparation method comprises the following steps: dissolving iron chloride hexahydrate and 1,4-benzenedicarboxylic acid in dimethylformamide, and obtaining a metal organic framework MIL-53Fe by using a hydrothermal method; dissolving silver bromide and bismuth bromide in preheated hydrobromic acid, then adding cesium bromide, and obtaining hexabismuth bismuth silver acid dicyesium by using an acid precipitation method; dissolving the metal organic framework MIL-53Fe and the hexabismuth bismuth silver acid dicyesium in anhydrous ethanol, and obtaining the hexabismuth bismuth silver acid dicyesium / metal organic framework MIL-53Fe heterojunction photocatalyst by using a mechanical stirring method. The formation of the heterojunction can greatly improve the photocatalytic reduction activity of the hexabismuth bismuth silver acid dicyesium / metal organic framework MIL-53Fe on carbon dioxide.

The invention discloses a preparation method and application of high-stability perovskite fluorescent powder based on a green solvent, and belongs to the technical field of luminescent materials, the preparation method is used for preparing the perovskite fluorescent powder, and the preparation method comprises the following steps: dissolving cesium bromide and lead acetate in deionized water, stirring to dissolve the cesium bromide and the lead acetate, adding a cationic surface active agent, and stirring to obtain a mixed solution; performing ultrasonic treatment after stirring to obtain an aqueous solution; adding betaine into absolute ethyl alcohol, stirring and dissolving to obtain an alcoholic solution, dropwise adding the aqueous solution into the alcoholic solution, and stirring at room temperature to obtain green fluorescent powder; and adding absolute ethyl alcohol into the green fluorescent powder for centrifugation, and performing vacuum drying on the centrifuged powder to obtain the perovskite fluorescent powder. The prepared perovskite fluorescent powder overcomes the defects that a traditional process depends on an organic solvent and a high-temperature reaction, the cost is high and a product is easy to deliquesce, and has relatively high fluorescence efficiency and stability.