290 results about "Silver nitrate" patented technology

The invention belongs to the technical field of drying equipment, and particularly relates to a double-cone vacuum dryer and a silver nitrate drying method.The double-cone vacuum dryer comprises a stock bin, a gas circuit mechanism, a heat source mechanism, a first power mechanism, a blowing adjusting mechanism and a second power mechanism; a second power mechanism drives an arc-shaped plate in a blowing adjusting mechanism to rotate back and forth relative to the transfer bin so as to adjust the direction and the flow speed of the hot nitrogen blown out of an upper opening of the transfer bin, and when the arc-shaped plate rotates clockwise, the silver nitrate wet material which is turned upwards under the action of centrifugal force is blown away; the second power mechanism is matched with the blowing adjusting mechanism to adjust the blowing-out direction and the blowing-out flow speed of hot nitrogen in a reciprocating mode, it can be guaranteed that a dry layer on the surface of the silver nitrate wet material is broken, and the problem that the silver nitrate wet material splashes after the dry layer on the surface of the silver nitrate wet material is broken can be solved; the problems that after a drying layer is formed on the surface of the silver nitrate wet material, the internal heat and mass transfer path is lengthened, and the drying efficiency and the drying time are affected are solved.

The invention provides high-filling silver powder and a preparation method thereof, and belongs to the field of metal powder.The preparation method comprises the steps that a nano-silver solution is prepared, a dispersing agent and a first reducing agent are mixed to obtain a mixed solution, the nano-silver solution and the mixed solution are mixed in a constant-temperature stirring state to obtain a base solution, a second reducing agent solution and a silver nitrate solution are prepared respectively, and the high-filling silver powder is prepared. And under the constant-temperature stirring state, the second reducing agent solution and the silver nitrate solution are synchronously added into the base solution, a silver powder solution is obtained through reaction, the silver powder solution is subjected to washing, solid-liquid separation, drying and depolymerization shaping treatment, and the high-filling silver powder is obtained. Controllable preparation of the large-size sphericity silver powder is achieved by controlling the particle size and the adding amount of the nano-silver, regulating and controlling heterogeneous nucleation and growth sites of silver ions and inhibiting formation of multistage dendritic crystals, surface charges and steric hindrance effects of silver particles are optimized through the surface adsorption effect of the dispersing agent, the agglomeration phenomenon of the silver powder in the growth process is reduced, and the silver powder is prepared. And meanwhile, the silver powder is endowed with excellent flowability.

The invention relates to a metallized microbubble and a preparation method thereof, a construction method of a multifunctional composite probe, and a rapid bacterium capturing and sterilizing method, and belongs to the technical field of functional material preparation. The method aims at solving the technical problems that in the prior art, a metal coating on the surface of the hollow glass microbubble is not uniform, combination is not firm, and stability is poor. According to the technical scheme, the method is characterized by comprising the following steps: mixing surface-activated hollow glass microbubbles with a polyethyleneimine solution for reaction, and washing and drying to obtain polyethyleneimine-coated hollow glass microbubbles; then reacting with a single-stranded DNA buffer solution to obtain an intermediate product loaded with DNA; then introducing a silver nitrate solution to load silver ions on the surface of the compound; and finally, reducing through a sodium borohydride solution to prepare the metallized microbubbles. The metalized microbubbles prepared by the method can be used for constructing a multifunctional composite probe to realize efficient capture and synergistic antibiosis of targets such as bacteria.

The invention belongs to the technical field of silver nitrate conveying, and particularly relates to a silver nitrate low-temperature drying cylinder, a discharging device and a discharging method.The device comprises a material cylinder, a feeding device, a discharging device and a discharging method.The upper end face of the material cylinder is provided with a discharging box, and the center of the discharging box is provided with a discharging channel; semicircular grooves are symmetrically formed in the inner wall of the discharging channel. The discharging device is arranged in the discharging channel, and two movable plates in the discharging device are arranged in the corresponding semicircular grooves respectively; wherein the two movable plates are arranged in an inverted cone shape; the two movable plates are suitable for deflecting to be in a conical shape when materials are stacked in the discharging box so that rapid discharging can be achieved.

The application belongs to the technical field of drying equipment, and particularly relates to a double-cone vacuum drying machine and a silver nitrate drying method. The double-cone vacuum drying machine comprises a stock bin, a gas path mechanism, a heat source mechanism, a first power mechanism, a blowing adjustment mechanism and a second power mechanism. The second power mechanism drives the arc-shaped plate in the blowing adjustment mechanism to reciprocatingly rotate relative to the transfer bin, so as to adjust the direction and flow rate of the hot nitrogen gas blown out of the upper opening of the transfer bin. When the arc-shaped plate rotates clockwise, the wet silver nitrate material that is flipped upward under the action of centrifugal force is blown away. The second power mechanism cooperates with the blowing adjustment mechanism to reciprocatingly adjust the blowing direction and blowing flow rate of the hot nitrogen gas, which can not only ensure that the dry layer on the surface of the wet silver nitrate material is broken, but also avoid the problem that the wet silver nitrate material splashes after the dry layer on the surface of the wet silver nitrate material is broken. That is, the problem that the heat and mass transfer path inside the wet silver nitrate material is lengthened after the dry layer is formed on the surface of the wet silver nitrate material, which affects the drying efficiency and drying time, is overcome.

The invention provides a GelMA microneedle patch loaded with chromogenic gold nano bipyramids and a preparation method thereof.The method comprises the steps that citric acid, chloroauric acid and a CTAC solution are mixed, then sodium borohydride is added, and a seed solution is obtained through stirring and standing; mixing chloroauric acid, silver nitrate, hydrochloric acid and CTAB (cetyltrimethyl ammonium bromide), and sequentially adding ascorbic acid and the seed solution to obtain a growth solution; carrying out centrifugation, morphology regulation and chemical etching purification to obtain a chromogenic gold nano bipyramid solution; the preparation method comprises the following steps: reacting gelatin with methacrylic anhydride in PBS, dialyzing and freeze-drying to obtain GelMA; dissolving GelMA in the gold nanoparticle bipyramid solution, and adding a photoinitiator LAP to obtain a mixed precursor solution; and the GelMA microneedle patch loaded with the gold nano bipyramid is prepared through mold casting, centrifugation, ultraviolet light crosslinking and drying demolding. The microneedle extraction and gold nano bipyramid color development integrated scheme is initiated, blood sampling is not needed, the dermis interstitial fluid is extracted in a minimally invasive mode through the microneedle, detection pain and trauma are reduced, the cross infection risk of blood treatment is avoided, and the microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle microneedle

The invention provides a preparation method of a metal-based ceramic composite membrane with a catalytic ozone function. The preparation method comprises the following steps: preparing functional powder by taking tetrabutyl titanate as a titanium source and silver nitrate or ferric nitrate as a catalytic active metal source and adopting a sol-gel method; a porous metal pipe is used as a supporting body, metal powder and functional powder which are made of the same material as the supporting body are mixed to prepare functional slurry, the functional slurry is evenly deposited on the inner wall of the supporting body through vacuum filtration, and powder particles which are not firmly combined are removed through back flushing; and finally, the binding force between the functional film layer and the metal matrix is improved through high-temperature heat treatment. Wherein the thermal expansion coefficient difference between the metal supporting body and the functional film layer can be reduced by adding the metal powder, the metal powder is melted and diffused in the high-temperature heat treatment stage, and metallurgical bonding is formed between the functional powder and the metal substrate. The method is simple in process, and the prepared metal-based ceramic composite membrane has the advantages of being high in membrane layer binding force, not prone to falling off, high in catalytic activity, high in anti-pollution capacity, stable in operation and the like.

The invention relates to the technical field of silver nitrate preparation, in particular to a production method of high-purity silver nitrate. According to the method, impurities are precipitated by adopting an impurity removing agent, then the impurities are removed by utilizing solid-liquid separation, and impurity metals and impurities in the silver nitrate solution are subjected to chemical reaction and physical solid-liquid separation by virtue of three-stage precision filtering equipment, so that the impurity content of the separated silver nitrate solution is relatively low, and meanwhile, the filtering parameter requirements are specified; according to the method, impurities are effectively removed, introduction of other ions is avoided, the purity of silver nitrate is guaranteed, the production efficiency is improved, the risk of secondary pollution is reduced, the product quality is improved, the production period is shortened, the single-batch treatment capacity is large, the product yield is high, the labor amount is reduced, and labor personnel are reduced.

The application discloses a kind of high-conductivity MXene-based electromagnetic shielding composite films and preparation method thereof, belong to new material technical field.The preparation method includes the following steps: using in-situ HF etching method to prepare MXene dispersion liquid;With deionized water as solvent, silver nitrate solution is prepared by dissolving silver nitrate;The silver nitrate aqueous solution is added to MXene dispersion liquid, and Ag@MXene film is obtained by vacuum filtration method.The method uses silver ion in silver nitrate as oxidant to make it and titanium element in MXene occur redox reaction to generate silver particles, so as to prop up MXene sheet layer and reduce the resistance caused by adhesion between sheet layers and increase the conductive path in MXene, so as to increase the conductivity of MXene;The composite film not only has excellent conductivity, electromagnetic shielding performance and is easy to form processing;The conductivity of the composite film can reach 3120S / cm, and the electromagnetic shielding performance can reach 68.5dB.

The invention provides silver powder with narrow particle size distribution and a preparation method thereof, and the preparation method comprises the following steps: dispersing silver nitrate in deionized water to obtain a solution A; dispersing a reducing agent in deionized water to obtain a solution B; dispersing a dispersing agent in deionized water to obtain a solution C; dispersing a coating agent in absolute ethyl alcohol to obtain a solution D; mixing the solution A and the solution C with set metering, heating to 60-70 DEG C to obtain a mixed solution, adding the solution B into the mixed solution, and stirring for reaction; when the concentration of Ag < + > in the mixed solution is reduced to 40-60%, adding the residual solution C into the mixed solution, reducing the temperature of the mixed solution to 40-50 DEG C, and continuing to add the solution B until charging is completed to obtain a reaction solution; and the solution D is added into the reaction solution, and the narrow-particle-size-distribution silver powder is obtained after the reaction is finished. The problems of secondary nucleation and non-uniform particle size distribution caused by improper addition of the dispersing agent when the silver powder is prepared by a chemical reduction method are solved by dynamically regulating and controlling the dispersing agent.

The invention relates to the technical field of environmental analytical chemistry, and discloses a thymol phenolphthalein-TBPE double indicator-based cyanide titration detection method and system, and the method comprises the following steps: adjusting a water sample to be detected to an alkaline pH interval to construct a detection matrix; the method comprises the following steps: introducing a double-indicator system composed of thymol phenolphthalein and tetrabromo phenolphthalein ethyl ester according to a specific ratio into a detection matrix, and constructing a spectrum background for masking yellow interference of sulfide by utilizing the blue color development characteristic of thymol phenolphthalein; dropwise adding a silver nitrate standard solution into the mixed system to execute a complex reaction; according to the method, a spectrum background shielding field is constructed, chromaticity response of a system in a specific wave band is monitored in real time, and when a chromaticity mutation signal from green to bluish violet is captured, a titration end point is judged, and the cyanide concentration is calculated. High-precision anti-interference detection on cyanide in a complex high-turbidity matrix is realized, and the sensitivity and accuracy of end point recognition are improved.

The invention provides a silver substrate and a preparation method and application thereof.The preparation method comprises the steps that firstly, dispersed silver seeds are introduced to the surface of an aluminum-foil paper substrate through the reaction of silver nitrate and excessive alkali, and in-situ nucleation sites are provided for follow-up silver growth; and then, through in-situ reduction reaction of hydroquinone and silver nitrate, silver controllably grows on the basis of the silver seeds to form a structure rich in hot spots. Conventional raw materials such as aluminum foil, silver nitrate, alkali and hydroquinone are adopted in the whole process, complex equipment is not needed, and therefore the process is simple and low in cost; meanwhile, a step-by-step regulation and control mechanism ensures that a large number of'hot spots' formed by nano-structure gaps and tips are formed on the surface of the silver substrate, and the key structure can obviously enhance Raman signals, so that the high-sensitivity detection requirement is met. In conclusion, the method has the advantages of preparation convenience, cost and high performance of the product, a practical substrate which is easy to popularize and high in adaptability is provided for the field of surface enhanced Raman spectrum detection, and the method has remarkable application value.

The invention relates to a silver recovery technology, in particular to a method for preparing high-purity silver powder by recovering silver from retired photovoltaic module cells, which comprises the procedures of pretreatment, leaching treatment, suction filtration treatment, silver precipitation treatment, silver chloride precipitation and purification treatment, silver ammonia solution reduction and the like. The method comprises the following steps: by taking a disassembled retired photovoltaic module battery piece as a raw material, firstly, removing dust on the surface of the battery piece and metal impurities partially attached to the surface of the battery piece through pretreatment, leaching the cleaned battery piece by using a nitric acid solution, carrying out suction filtration by using a suction filtration machine, and separating to obtain silicon slag and a silver nitrate solution; the method comprises the following steps: adding a chlorinating agent into a silver nitrate solution, reacting to generate silver chloride precipitate, dissolving the separated silver chloride precipitate by using ammonia water to form a silver-ammonia solution, and finally adding a reducing agent into the silver-ammonia solution to obtain high-purity silver powder and ammonia water; compared with the conventional technology, the method for recovering silver has the advantages of low cost, no wastewater generation and simpler process, and meets the requirements of economy, high efficiency and environmental protection.

The invention provides silver powder with high crystallinity and narrow particle size distribution and a preparation method thereof, and belongs to the technical field of metal powder preparation. The preparation method comprises the following steps: preparing a silver nitrate solution, an ascorbic acid solution, a stabilizer solution, a dispersant solution, a seed crystal solution, a nitric acid solution and a surface modifier solution; adding the stabilizer solution and the nitric acid solution into the seed crystal solution, and mixing to obtain a solution A with specific PH; the dispersing agent solution is added into the silver nitrate solution for mixing, and a solution B is obtained; adding the solution B and an ascorbic acid solution into the solution A, fully reacting, and collecting a precipitate; and washing the precipitate, adding a surface modifier solution, fully stirring, drying, and dispersing to obtain the target silver powder. Different reaction mixed solutions are prepared step by step and then mixed according to a specific sequence, and the submicron silver powder with the high crystallinity and the large specific surface area is prepared through a simple and controllable method.

The invention discloses low-activity sintering-resistant silver powder and a preparation method thereof, and belongs to the technical field of precious metal powder materials. The preparation method comprises the following steps: S1, dissolving a reducing agent and a dispersing agent in water, adding a silver nitrate solution, and reacting to obtain a seed crystal solution; s2, adding the seed crystal solution into a dispersing agent solution, and adding a silver nitrate solution and a reducing agent solution at the same time to obtain a reaction mixture; and S3, the reaction mixture is subjected to impurity removal, drying, crushing and sieving, and the low-activity sintering-resistant silver powder is obtained. The prepared silver powder is large in particle size, high in tap density, small in specific surface area and low in burning loss, and is mainly applied to silver-palladium resistance paste or silver-palladium-platinum resistance paste of a thick film heating module.

The invention relates to the technical field of photocatalytic materials, in particular to a multi-ion doped TiO2 nanosheet material suitable for degradation of dyes in water and a preparation method of the multi-ion doped TiO2 nanosheet material. The preparation method comprises the following steps: pre-embedding a self-sacrifice template in a germanium-tungsten composite doping solution, carrying out hydrothermal conversion to construct a Ge-W synergetic optimized regular TiO2 substrate, carrying out atomic layer deposition to realize nitrogen / silver uniform doping, and carrying out synergetic surface modification on silver nitrate-ethanolamine and perfluorosilane to prepare the TiO2 nanosheet material. Germanate serves as lattice strain guidance to guide TiO2 lattice growth to form a low-defect matrix, tungstate is cooperatively doped in the matrix to construct a strong built-in electric field to improve the charge separation efficiency, Ge-W elements cooperate to stabilize a bulk phase and a grain boundary, and a gradient protection barrier is constructed with selective shielding of a fluorosilane layer. The TiO2 catalyst is synergistically improved in the aspects of high catalytic activity and long-acting environmental stability, and is suitable for efficient pollutant purification in a complex water quality environment.

This invention discloses an ultra-low roughness chemical silver plating solution for 6G communication, comprising 2-5 g / L silver nitrate, 10-15 g / L complexing agent, 5-8 g / L nicotinic acid, 2-5 g / L reducing agent, 1-3 g / L stabilizer, 0.1-0.5 g / L surfactant, 10-30 g / L pH adjuster, 0.01-0.1 g / L grain refiner, 0.1-0.5 g / L antioxidant, and water. The invention also provides a method for its preparation. Compared with existing technologies, this invention uses specific halogenated compounds to modify uracil, improving its defects and making it less prone to ionization. The introduced groups also impart crystal plane guiding function, thereby achieving an ultra-low surface roughness of the plating layer.

The invention belongs to the field of nano materials, and particularly relates to an indium selenide nanosheet compound as well as a preparation method and application thereof. The preparation method provided by the invention comprises the following steps: mixing indium selenide nanosheets and silver ions in a second solvent, so that silver nanoparticles grow on the surfaces of the indium selenide nanosheets; the second solvent is a polar solvent, the Hansen solubility parameter delta of the third solvent is greater than or equal to 18MPa < 1 / 2 >, and the mass ratio of the indium selenide nanosheets to the silver ions is (5-50): 1. And growing silver nano-silver particles on the surface of indium selenide by utilizing a spontaneous oxidation-reduction reaction of indium selenide and silver nitrate, so as to prepare the indium selenide nanosheet compound with the surface modified by the silver nano-silver particles. The silver nanoparticles have strong absorption, and the photoelectric response effect of the indium selenide nanosheet is remarkably improved by compounding the silver nanoparticles and the indium selenide nanosheet.

This invention discloses a method for preparing a silver- and aluminum-loaded attapulgite composite material and its application. The method involves mixing attapulgite with hydrochloric acid, reacting, drying, and grinding to obtain modified attapulgite. The modified attapulgite is then mixed with aluminum chloride solution and reacted, followed by drying to obtain aluminum-modified attapulgite. Silver nitrate, aluminum-modified attapulgite, and deionized water are mixed to obtain a mixed solution. KI solution is added dropwise to the mixed solution, and the mixture is stirred for 2–4 hours. After filtration, washing, drying, and grinding, a precursor material for the loaded material is obtained. This precursor material is then photoactivated in a photochemical reactor to obtain the silver- and aluminum-loaded attapulgite composite material Ag / AgI / Al. The Ag / AgI / Al material prepared by this invention exhibits good doping effects. Furthermore, in the composite material system, Ag, AgI, and Al produce a synergistic effect, resulting in a good degradation effect on methyl orange.

The invention discloses a preparation method of an MF (at) NH2 (at) Ag SERS (Surface Enhanced Raman Scattering) sensor for detecting paraquat and diquat, belongs to the field of nano material synthesis and spectral analysis, and solves the problems that a traditional detection method is complicated in process and cannot detect pesticides and free radicals thereof at the same time, and a traditional SERS substrate is poor in enhancement effect and low in stability. The preparation method comprises the following steps: firstly segmenting melamine foam, cleaning and drying, soaking in hydrochloric acid, soaking in a polyethyleneimine aqueous solution to modify amino, drying, soaking in a silver nitrate solution for ultrasonic treatment, adding a sodium borohydride solution under an ice bath, stirring and reducing, and finally cleaning and drying to obtain the sensor. The sensor takes three-dimensional melamine foam as a support, silver nanoparticles are uniformly loaded on the surface of the three-dimensional melamine foam, paraquat, aquacide and free radicals thereof are enriched through electrostatic interaction based on a localized surface plasma resonance principle, and Raman signal enhancement is realized. The detection limit is 10 <-9 > mol / L, the signal stability and repeatability are excellent, the applicability to actual water sample detection is good, the detection of other pesticides can be expanded, and the method is suitable for on-site rapid trace detection.

The invention belongs to the technical field of metallurgy, and relates to a method for testing gold in crude antimony crystal salt, which comprises the following steps: S1, roasting the crude antimony crystal salt at 280-320 DEG C for the first time, then heating to 550-650 DEG C, and roasting for the second time; and S2, after roasting is finished, a composite flux and a silver nitrate solution are added, heat preservation melting is conducted for 10-15 min at the temperature of 1150-1200 DEG C, a lead buckle is obtained, then the lead buckle is subjected to soot blowing, and the gold content in the crude antimony crystal salt is obtained through measurement. According to the method, the influence of sodium sulfide sulfate, sodium sulfide and sodium antimonate on gold content testing is solved through oxidizing roasting pretreatment; and the iron powder, the nickel powder and other composite fluxing agents are added in the subsequent melting process, and the gold content testing accuracy is remarkably improved.

The invention relates to a silver-nitrate recovery method comprising the process steps of preparing a nitric-acid solution in a reactor tank and feeding silver sludge into the prepared acid solution to obtain an intermediate product. The silver-nitrate recovery method further comprises introducing N2 onto the intermediate product, sweeping the resulting NOx gases with the introduced N2 and reacting them with H2O2 so as to eliminate them, and collecting the silver nitrate formed in a vessel.

This invention relates to the field of nano-silver powder preparation technology, specifically a method for preparing high-tap-density, high-purity silver powder. This invention overcomes the problems of insufficient purity and low tap density in existing silver powder technologies. The invention involves preparing a solution of silver nitrate, performing electrolytic pretreatment, and then obtaining a silver powder suspension through chemical reduction, co-precipitation, and dissolution-reduction processes. The silver powder suspension is then subjected to physical vapor deposition, where silver vapor is deposited onto the silver powder surface under the action of argon gas, resulting in a dense arrangement of silver powder particles. An electrolyte is then prepared using silver nitrate and bismuth nitrate for electrolytic refining. Finally, high-tap-density, high-purity silver powder is obtained through ultrasonic dispersion and supercritical fluid drying. By strictly controlling the process sequence and parameters, and utilizing the synergistic effect between each process, impurities are effectively removed, the particle size distribution of the nano-silver powder is optimized, and the purity and tap density of the nano-silver powder are improved, thus optimizing the application of silver powder in conductive materials.

The invention relates to the fields of environmental protection, fire protection and new materials, in particular to a nano-silver self-assembled efficient disinfectant synthesized by a water extract of epimedium stems. The method comprises the following steps: weighing 10 g of epimedium stem powder, putting the epimedium stem powder into a beaker, then adding 100 mL of purified water into the beaker, putting the beaker on an electrothermal furnace, heating until boiling, then heating for 30 min, after a solid-liquid mixture is cooled, filtering impurities by using gauze, centrifuging for 10 min at a speed of 4000 r / min, retaining supernate, and fixing the volume to 100 mL; 0.17 g of silver nitrate powder is weighed and added into a beaker, then 100 mL of purified water is added for dissolution, and a silver nitrate solution is prepared; adding 20mL of the water extracting solution of the epimedium stems after constant volume into the beaker; mixing the solution, and stirring for 2 hours by using a magnetic stirrer; and the temperature is 60 DEG C to obtain the herba epimedii water extract-nano-silver self-assembled solution.

The application discloses a preparation method of a photocatalyst for CO2 reduction and application thereof. The photocatalyst is prepared through the following steps: first, preparation of the photocatalyst bismuth oxysulfate; second, metal loading modification of the photocatalyst bismuth oxysulfate. Thiocyanic acid and bismuth nitrate are used as raw materials to synthesize the photocatalyst bismuth oxysulfate, and copper chloride or silver nitrate reagent is selected as a material for metal loading modification of the bismuth oxysulfate, and the selected materials are inexpensive and easy to purchase, and the economic cost is low. The photocatalyst prepared by the method has the advantages of high selectivity, can accelerate electron movement under light conditions, promotes CO2 reduction degradation, and has high stability, and is an ideal photocatalyst. Compared with existing photocatalyst materials, the material has high catalytic degradation reducibility and selectivity, high stability, and when used as a CO2 photocatalyst, can efficiently reduce and convert CO2 into multi-carbon products.

The application discloses a circulating water purification treatment process for heat exchange equipment and relates to the technical field of circulating water purification treatment, and comprises the following steps: preparing a polyaspartic acid-silane functionalized graft intermediate; selecting a porous zeolite matrix and performing acid activation treatment; immersing the matrix in sol, standing for defoaming, and performing temperature rising calcination to obtain a nano TiO2-coated zeolite matrix coated with nano titanium dioxide on the surface; immersing the nano TiO2-coated zeolite matrix in a solution, stirring and reacting after adjusting the pH value of the solution to obtain PASP functionalized zeolite filter material; immersing the PASP functionalized zeolite filter material in a silver nitrate solution, performing photocatalytic reduction, reducing and depositing silver ions in situ, and obtaining silver / titanium dioxide-polyaspartic acid synergistic functionalized composite filter material. Through the synergistic composite filter material, efficient scale inhibition and sterilization and rapid purification are realized, excellent stability and durability are exhibited under harsh working conditions such as high temperature and long period, the application is environment-friendly, and the maintenance cost is low.

This application provides a conductive polyimide film and its preparation method, belonging to the field of conductive materials. The method involves preparing a polyamic acid solution, mixing surface-coated rod-shaped silver powder with the polyamic acid solution, and then performing a casting process followed by gradient heating to obtain a polyamic acid film enriched with rod-shaped silver powder at the bottom. The rod-shaped silver powder-rich surface of the obtained polyamic acid film is then subjected to an ion exchange reaction with a silver nitrate solution. The ion-exchange film is then cleaned and subjected to thermal imidization treatment to obtain the conductive polyimide film. This application utilizes the ion exchange reaction and subsequent thermal curing process to reduce silver ions on the film surface, forming a silver-plated layer with excellent adhesion and conductivity. This material exhibits excellent reliability during use; even if the surface silver-plated film partially peels off due to wear, the conductive network built by the rod-shaped silver powder at the bottom can still serve as a backup conductive path, significantly improving its long-term stability in practical applications.

The invention relates to an Au / Ag / g-C3N4 composite material and a preparation method thereof.The preparation method comprises the steps that urea, silver nitrate and HAuCl4 are added into a clean beaker and tightly wrapped with tinfoil, deionized water is added for dissolution, and then magnetons are added and stirred on a magnetic stirrer in a dark place till the magnetons are completely dissolved; drying the mixture solution in a drying oven, grinding the mixture solution into powder by using an agate bowl after the mixture solution is completely dried, and putting the powder into a corundum porcelain boat; the preparation method comprises the following steps: performing thermal polymerization treatment on a mixed grinding material of urea, silver nitrate and HAuCl4, heating a tubular furnace to 540 DEG C under the protection condition of argon flow, keeping the constant temperature for 1-3 hours, and finally cooling the tubular furnace to room temperature in an argon atmosphere environment to obtain the Au / Ag / g-C3N4 composite material. Au and Ag are introduced to weaken hydrogen bonds in carbon nitride, so that the technical problem that future application of existing g-C3N4 is limited by specific surface area, insufficient visible light absorption and carrier recombination is solved.

The invention discloses a method for detecting boron and phosphorus impurities in photovoltaic polycrystalline silicon recovery hydrogen, and belongs to the technical field of detection of polycrystalline silicon recovery hydrogen, and the method comprises the following steps: taking two absorption bottles as sample absorption bottles, taking the other two absorption bottles as blank absorption bottles, and finally adding a silver nitrate solution into each absorption bottle; the two sample absorption bottles are connected in series and then installed on the sampler, then recycled hydrogen is introduced, the recycled hydrogen passes through the silver nitrate solution, the silver nitrate solution absorbs boron and phosphorus impurities in the recycled hydrogen, and the two sample absorption bottles are not connected with the sampler; weighing the two sample absorption bottles together with the internal solution, detecting by adopting an inductively coupled plasma mass spectrometer to obtain the content of boron and phosphorus impurity elements in the sample absorption liquid, and obtaining the content of boron and phosphorus impurity elements in the blank solution in the same detection mode; and calculating to obtain the content of boron and phosphorus impurity elements in the recovered hydrogen. The method can accurately detect the contents of boron and phosphorus elements in the recovered hydrogen.

The invention discloses a preparation method of nano silver-coated copper powder with a three-layer progressive structure, which comprises the following steps: by taking copper nitrate and silver nitrate as main raw materials, forming compact silver-coated copper powder with an inner layer as a large pure copper core, a middle layer as a copper-silver alloy gradient layer and an outer layer as a pure silver layer through various auxiliary agents and processes, and expanding to a micron level by taking nano application as a main part. The silver-coated copper is mainly used for replacing pure silver powder and silver-coated copper with a two-layer structure. In the application of electronics and other fields, the three-layer gradient compact gapless alloy structure enables multiple indexes such as structural strength, interlayer resistivity and the like to be superior to those of the two.