187 results about "Silver nitrate" patented technology

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 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 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 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 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.

The invention discloses a spiral chiral gold nanorod as well as a preparation method and application thereof, and the method comprises the following steps: (1) sequentially adding hexadecyl trimethyl ammonium bromide, cysteine and p-aminothiophenol into an anisotropic gold nanorod solution, uniformly mixing, and adsorbing; and (2) silver nitrate, chloroauric acid and ascorbic acid are added for a reaction, centrifugal dispersion is performed after the reaction is finished, and the spiral chiral gold nanorod is obtained. Dispersing the spiral chiral gold nanorod in an aqueous solution, adding phenylalanine enantiomer, dropwise adding on a clean glass slide after incubation is finished, and performing surface enhanced Raman spectroscopy test by using a Raman microscope after air drying. According to the invention, the broadband coverage of chiral response from visible light to near ultraviolet region is realized by accurately regulating and controlling the arrangement of interface molecules and the morphology of the nano structure.

The invention belongs to the technical field of silver nitrate preparation, and particularly relates to a pilot drying device for silver nitrate preparation, which comprises a box body, a drying chamber, a drying drum and a support and transmission structure matched with the drying drum, a vacuumizing pump is arranged on one side of the box body, a drum support frame and a drum driving motor are mounted in the drying chamber, and a rotating rod drives the drying drum to rotate through gear engagement; a feeding pipe and a blowing fan are arranged on a top plate of the box body in a penetrating manner, and the tail end of a hose is fixed in a feeding hole of the drying drum to realize continuous feeding; an air blower and an air supply pipe are arranged in the drying chamber, conical air nozzles uniformly distributed on the air supply pipe are aligned with air-drying windows on the wall of the drying drum to blow air, and filter cloth covers the surfaces of the air-drying windows to prevent impurities from entering; a discharging rod, a top frame, a lantern ring and a hanging ring are arranged on the box body and used for inclining the drying rotary drum, materials fall into a dry material storage barrel through a discharging nozzle, and then sealing collection is completed through a sealing rod, a C-shaped buckle and a barrel cover; and the blowing fan, the air blower, the barrel driving motor and the vacuumizing pump are electrically connected with the PLC.

The invention relates to the technical field of photocatalysis, in particular to a strontium bismuth vanadium oxide photocatalyst and a preparation method and application thereof.The chemical formula of the photocatalyst is Sr3. 59Bi19.41 V4O42, the crystal structure of the photocatalyst belongs to an orthorhombic system, the space group of the photocatalyst is Immm, and the photocatalyst is of a unique layered structure composed of cation triple plate layers; the photocatalyst is synthesized by a molten salt method, and shows the activity of photocatalytic decomposition of water to produce oxygen under visible light. The preparation method comprises the following steps: mixing and grinding SrO, Bi2O3 and VO precursors with a molten salt medium, and then carrying out temperature programming calcination to synthesize a target product; the catalyst prepared by the method has the characteristics of high crystallinity, few defects and regular morphology, the photocatalytic oxygen production performance of the catalyst is remarkably superior to that of a same-component sample synthesized by a traditional solid-phase method, and photocatalytic water decomposition and oxygen production can be realized by taking a silver nitrate, ferric nitrate, ferric chloride or potassium ferricyanide aqueous solution as a sacrificial agent system under the irradiation of visible light with the wavelength of more than or equal to 420 nm.

This invention discloses a soil chloride ion detection pretreatment device, its usage method, and a filter paper preparation method, relating to the field of laboratory equipment technology. The device includes a funnel placement rack with a double-compartment funnel inserted inside. Eight evenly distributed structural support ribs are fixedly installed on the inner wall of the double-compartment funnel. Folded composite filter paper and a nylon support mesh are placed sequentially on the structural support ribs. The upper layer of dilute nitric acid is used to wash away chloride from the activated carbon fiber layer, efficiently adsorbing colored substances such as humus and organic matter in the soil extract. This results in a clear and transparent filtrate, eliminating the interference of deep yellow and brown to the brick-red endpoint of the silver nitrate titration method. The endpoint is clearly distinguishable, and the chloride ion recovery rate is stabilized at 92.0%–105.0%. This solves the problem of the lack of a decolorization step in the silver nitrate titration method, leading to a blurred endpoint and a detection error of over 20% caused by high-chroma soil extract.

The application belongs to the technical field of photocatalytic nanomaterials, and relates to a preparation method of Nb2O5@Ag3PO4 composite material, which comprises the following steps: a. dissolving niobium oxalate in a mixed solution of deionized water and hydrogen peroxide, and magnetically stirring to obtain solution A; b. adding ammonia water into solution A, magnetically stirring, and hydrothermally reacting, and then treating the product after the reaction to obtain white powder B; c. dissolving powder B in anhydrous ethanol, and ultrasonically and stirring to mix to form a uniform mixed solution C; d. respectively dissolving silver nitrate and sodium phosphate in deionized water to form solutions D and E for standby; e. dropping solution D into solution C at a certain rate to obtain solution F; f. dropping solution E into solution F at a certain rate, and then centrifuging, cleaning and drying at a constant temperature for a certain time to obtain the Nb2O5@Ag3PO4 composite material. The application has the advantages of simple process, low cost, short reaction period, no pollution to the environment, and visible light photocatalytic performance.

This invention relates to the field of nanocomposite materials technology, specifically to a carbon-based silver sulfide composite aerogel with synergistically enhanced light-harvesting and biofouling resistance, its preparation method, and its applications. The method involves pouring a chitosan-graphene solution into a polystyrene mold and using different cryogenic casting methods to obtain chitosan-graphene aerogels with different orientations. Carbonization under a N2 atmosphere yields carbon-based aerogels with different structures. Immersion in a tannic acid-Tris solution allows for the adsorption of tannic acid molecules. After washing with deionized water, the aerogels are immersed in a silver nitrate solution to form tannic acid-silver ion complexes. Further washing with deionized water and immersion in a thioacetamide solution yields carbon-based silver sulfide composite aerogels with different structures. This method solves the problem of performance loss due to biofouling in carbon-based three-dimensional porous materials. The carbon-based silver sulfide aerogel exhibits superior light absorption and photothermal properties compared to carbon-based zinc oxide aerogels, overcoming the problem of weakened evaporation performance in conventional anti-biofouling designs.

This application relates to the field of metal composite material preparation technology, and in particular to a preparation device and process for silver-coated copper powder, including a support and a preparation mechanism; the support includes a mounting plate and four supporting legs fixed in a rectangular array on the lower surface of the mounting plate; the preparation mechanism includes a reaction vessel, and the upper surface of the mounting plate has mounting holes for mounting the reaction vessel. The interior of the reaction vessel, from top to bottom, is provided with a pretreatment chamber and a reaction chamber. The top of the reaction vessel is respectively provided with a first addition funnel and an additive addition cylinder. By setting up the preparation mechanism, this scheme disperses copper powder using ultrasound and additives, adds a reducing agent to control the reaction rate, and, under the action of a pneumatic atomizer, ensures that the reducing agent is fully diffused in the silver nitrate solution, ensuring uniform and stable reduction of silver ions, thereby controlling the thickness of the silver layer on the copper surface.

The invention relates to the technical field of micromachining and surface engineering, and discloses a variable cross-section sampling needle tube inner wall electrochemical discharge additive and subtractive material synergistic preparation method which comprises the following steps: adsorbing magnetic nano powder to a magnet electrode handle to assemble a flexible tool electrode; the flexible tool electrode is inserted into a sampling needle tube injected with electrolyte containing silver nitrate and low-surface-energy substances, a local thermal field is generated through electrochemical discharge, and the flexible tool electrode is extruded in a reducing area to force powder to be rearranged to actively adapt to pore diameter changes. According to the method, the micro-nano nested structure is etched through electrochemical discharge, the recast layer is removed through mechanical grinding of adsorbed magnetic nano powder, antibacterial particles and low-surface-energy substances are induced to be co-deposited in situ through a discharge thermal field, and the silver antibacterial coating is formed in the micro-nano nested structure. The integrated cooperation of variable cross-section deep hole inner wall material removal, surface finishing and functional coating preparation is realized, and the inner wall of the sampling needle tube is endowed with hydrophobic and antibacterial properties.

The invention belongs to the field of preparation of organic-inorganic hybrid materials, and relates to a preparation method and application of cucurbit [n] uril-gold nanoparticles. Through a simple one-pot synthesis method, chloroauric acid, silver nitrate, a reducing agent and cucurbit [n] uril are added for co-reduction to prepare hollow gold nanoflowers; the gold nanospheres with different sizes are prepared by regulating and controlling the input amount of cucurbit [n] uril. The gold nanoparticle hybrid material shows excellent hydrogen evolution side reaction inhibition capability in the application of electro-catalysis CO2 reduction, and the CO selectivity is obviously improved.

The invention belongs to the technical field of conveying, and particularly relates to an accurate matching conveying device for silver nitrate production and a production process. The invention provides an accurate proportioning and conveying device for silver nitrate production, which comprises a metering pump, a water outlet end of which is provided with a connecting pipe communicated with an accommodating tank; the adjusting assembly is hinged to the water outlet of the connecting pipe, and the adjusting assembly is suitable for opening and closing the connecting pipe; when the metering pump conveys liquid into the containing tank, the fluid pushes the adjusting assembly to turn over outwards. The adjusting assembly is suitable for blocking the water flow direction at the water outlet of the connecting pipe; when the metering pump stops working, the adjusting assembly is suitable for sealing the water outlet so that the connecting pipe can be filled with liquid. When the metering pump conveys liquid into the containing tank, the adjusting assembly can adjust the water flow direction of the liquid, and the situation that the liquid is splashed out of the containing tank due to too large pressure is avoided; and when the metering pump stops working, the volume of the liquid actually flowing into the accommodating tank can be accurately metered, so that the conveying and metering accuracy is improved.

The invention discloses a radioactive methyl iodide filtering material and a preparation method thereof, and belongs to the technical field of nuclear fuel waste gas treatment. The preparation method comprises the following steps: preparing a nitrogen-carbon skeleton from a reaction monomer through a cross-linking reaction; dispersing the nitrogen-carbon skeleton, a silver nitrate solution and an ionic liquid in water to obtain a mixed solution; the mixed solution is subjected to nano silver oxide in-situ growth in the environment of ultraviolet lamp irradiation and ultrasonic oscillation, and the radioactive methyl iodide filtering material is prepared. The radioactive methyl iodide filtering material is a nano silver oxide in-situ loaded nitrogen-carbon skeleton composite material and can be used as a radioactive methyl iodide filtering and storing material, efficient adsorption of radioactive methyl iodide is achieved through the chemical adsorption effect of nano silver oxide and methyl iodide, meanwhile, it is ensured that the adsorption process is stable and irreversible, and the radioactive methyl iodide filtering material can be used for filtering and storing radioactive methyl iodide. And no methyl iodide is released in a deep stratum treatment environment.

This invention discloses a method for preparing near-spherical polycrystalline silver powder for solar cell electrode paste, comprising the following steps: S1, preparing solution A: dissolving silver nitrate in deionized water and adding ammonia water with a mass concentration of 25%; S2, preparing solution B: dissolving a reducing agent in water, stirring continuously, and then adding a surfactant and NaOH solution; S3, preparing solution C: dissolving 200-300g of dispersant in water to obtain a base solution; S4, starting stirring, adding solution A and solution B concurrently to solution C at a rate of 0.2-1.2 L / min; S5, separating the silver powder into solid and liquid phases and washing it until the conductivity is <20 μs / cm to obtain a silver powder filter cake; S6, adding a surface treatment agent solution to the silver powder filter cake, stirring evenly, then drying, mechanically dispersing, and sieving to obtain near-spherical silver powder with a particle size of 1.3-2.5 μm.

The invention relates to the technical field of metal powder, in particular to flake silver powder and a preparation method and application thereof.The preparation method of the flake silver powder comprises the steps that S1, silver nitrate and a composite morphology control agent are added into deionized water and mixed to be uniform, and a precursor solution is formed; s2, treating the precursor solution by using ultrasonic waves; s3, heating the precursor solution subjected to ultrasonic treatment to a preset temperature, and adding a reduction solution into the precursor solution to form a suspension; and the turbid liquid is treated, and the flake silver powder is prepared. The cavitation effect of ultrasonic waves not only provides a high-energy nucleation point location, but also optimizes the adsorption and arrangement state of molecules of the composite morphology control agent around silver crystal nuclei, so as to synergistically induce oriented growth of silver atoms. Ultrasonic pretreatment and a composite morphology control agent are organically combined, the synergistic effect between the ultrasonic pretreatment and the composite morphology control agent is utilized, the flaky silver powder with a unique micro-nano-scale wrinkle structure can be prepared, the tap density of the produced silver powder is smaller than 2.0 g / cm < 3 >, and the specific surface area of the produced silver powder is larger than 2.0 m < 2 > / g.