421 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 discloses silver powder with coexisting submicron sheets and nano-particles and a preparation method of the silver powder, and belongs to the technical field of silver powder preparation. A silver nitrate solution is added into a dispersing agent solution, then a directional end-capping reagent solution is added, and nucleation and growth of submicron sheets and nano-particles are controlled through the types of dispersing agents, the types of directional end-capping reagents, the temperature gradient and the like. The diameter of the prepared flaky silver powder ranges from 0.1 micrometer to 1.5 micrometers, the thickness of the flaky silver powder ranges from 30 nm to 120 nm, and the flaking rate ranges from 30% to 90%. And the particle size of the spherical silver powder is 30-150 nm. According to the preparation method of the silver powder, a silver nanocrystal seed solution does not need to be prepared independently, and the silver powder is different from common silver powder with single morphology, can be used for preparing the flake-shaped and particle-shaped coexisting silver powder in one pot, and is suitable for being used as a conductive functional phase of low-temperature curing type electronic paste.

The invention relates to the technical field of nano silver powder preparation, in particular to a preparation method of high-tap-density and high-purity silver powder. The problems that in the prior art, silver powder is insufficient in purity and low in tap density are solved. The method comprises the following steps: preparing silver nitrate into a solution, carrying out electrolytic pretreatment, and carrying out chemical reduction, coprecipitation and dissolution reduction to obtain a silver powder suspension; the silver powder suspension is subjected to physical vapor deposition, silver vapor is deposited on the surface of the silver powder under the action of argon, and silver powder particles are tightly arranged; preparing an electrolyte from silver nitrate and bismuth nitrate, and carrying out electrolytic refining; and finally, the high-tap-density high-purity silver powder is obtained through ultrasonic dispersion and supercritical fluid drying treatment. By strictly controlling the process sequence and parameters and utilizing the synergistic effect among the processes, impurities are effectively removed, the particle size distribution of nano silver powder particles is optimized, the purity and tap density of the nano silver powder are improved, and the application of the silver powder in conductive materials is optimized.

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 provides a preparation method and application of coating enhanced nano silver powder. The preparation method comprises the following steps: S1, preparing nano silver by taking silver nitrate as a silver source and polyethyleneimine as a reducing agent; s2, carrying out coating modification on the nano-silver by adopting aniline and ammonium persulfate under an acidic condition; s3, modifying the polyaniline coated nano-silver by adopting chloroacetic acid to obtain chloroacetic acid modified polyaniline coated nano-silver; s4, preparing a modified graphene oxide dispersion liquid; s5, partially reducing the graphene oxide; s6, partially reduced graphene oxide is adopted to load the chloroacetic acid modified polyaniline coated nano-silver, polyaniline coating and reduced graphene oxide compounding are carried out, and the dispersity and stability of nano-silver particles are effectively improved. The oxidation state of polyaniline promotes the release of silver ions through an electron transfer effect, so that the antibacterial effect is enhanced; and the partially reduced graphene oxide synergistically accelerates the release of silver ions, so that the antibacterial property is further improved.

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 invention discloses an AgVO material with modified vanadium dioxide doped with silver ions, a preparation method of the AgVO material and application of the AgVO material in an aqueous zinc ion battery. The silver ion doped modified vanadium dioxide AgVO material is prepared by the following steps: firstly, enabling vanadium pentoxide and anhydrous oxalic acid to react in water to obtain a clear dark blue solution; and then carrying out hydrothermal reaction on the dark blue solution and silver nitrate at 175-185 DEG C to obtain the silver vanadium oxide composite material with a nanofiber bundle microstructure, wherein the silver vanadium oxide composite material is formed by doping silver ions on the surface and inside of a VO2 material. The silver ion doped modified vanadium dioxide AgVO material provided by the invention has a nanofiber bundle microstructure, and an aqueous zinc ion battery taking the silver ion doped modified vanadium dioxide AgVO material as a positive electrode active material has excellent capacity, cycling stability and rate capability and excellent electrochemical performance.

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 relates to the technical field of titration detection in analytical chemistry, in particular to a thymol phenolphthalein-TBPE composite indicated cyanide high-precision detection method which comprises the following steps: step 1, after a water sample to be detected is distilled and separated, adjusting the pH value of distillate to a strong alkaline environment required by thymol phenolphthalein color development; 2, adding a composite indicator containing thymol phenolphthalein and tetrabromo phenolphthalein ethyl ester, wherein the mass ratio of the two components in the composite indicator is determined through a color change sensitivity optimization experiment; step 3, titrating with a silver nitrate solution, and judging an end point according to three-order color mutation: the initial state is light yellow, the intermediate state is green, and the end point state is purple red; and 4, adding an auxiliary masking agent before titration, and blocking the reaction between the auxiliary masking agent and silver ions by preferentially complexing interference ions. By optimizing the ratio of the composite indicator and using the masking agent, interference of other substances can be effectively prevented, and accurate detection of cyanide is ensured.

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 belongs to the technical field of photovoltaic module recycling, and discloses a method for efficiently extracting and recovering valuable components from waste solar cell fragments, which comprises the following steps: firstly, carrying out aluminum removal leaching by using chlorate, then carrying out silver extraction leaching by using a choline chloride / ethylene glycol / water / mixture as a silver leaching solvent, and finally, carrying out high-efficiency recycling on the valuable components. Diluting the silver leaching solution to obtain silver chloride with relatively high purity; and finally, carrying out silicon nitride removal leaching through a hydrogen fluoride solution to obtain a high-purity silicon-containing material. By the adoption of the method, the aluminum removal rate reaches up to 97% or above, the non-silver nitrate leaching solvent is adopted, the purity of obtained silver chloride is larger than 97%, the silicon material with the purity larger than 99% is finally obtained, and efficient, economical and environment-friendly comprehensive extraction and recovery of the waste solar cell fragments are achieved.

The invention discloses flake silver powder and a preparation method thereof, and belongs to the technical field of silver powder. The preparation method of the flaky silver powder comprises the following steps: mixing a reducing agent solution, a template agent solution and a reaction solvent to obtain a first mixed solution; mixing a silver nitrate solution with the first mixed solution to obtain a second mixed solution with initial flake silver powder; and mixing the sintering aid solution with the second mixed solution so as to coat the initial flake silver powder. According to the method, the reducing agent solution and the silver nitrate solution are subjected to one-step reduction reaction in the presence of the template agent solution, the flaky silver powder can be obtained within a short time, the production process is simple and environmentally friendly, and large-scale production is facilitated; after the initial flake silver powder is obtained, the sintering aid solution is combined, and the morphology and sintering activity of the flake silver powder can be effectively controlled. The flaky silver powder obtained through the method is narrow in particle size distribution and uniform in dispersion, the proportion of flaky silver powder is high, and the flaky silver powder can be applied to low-temperature sintering.

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 invention discloses silver-coated copper powder with a uniform silver layer and a preparation method and application of the silver-coated copper powder, and relates to the technical field of conductive materials and metal powder preparation.The silver-coated copper powder is characterized in that organic matter and an oxide layer on the surface of copper powder are removed through an acidic or alkaline solvent, and then a small amount of alcamines reagent is added and evenly stirred to serve as a copper powder interface reduction protective agent; then, one reagent of silver nitrate, silver ammonia and a silver nitrate-alkylol amine complexing solution is added to serve as a seed layer silver plating solution; according to the method, the silver layer coating stability of the silver-coated copper powder in the prior art can be improved, the coating surface of the silver layer is smoother, coating is more complete, the phenomenon that a copper core is exposed is reduced, and the silver-coated copper powder with the uniform silver layer coating is obtained. And the volume resistivity is relatively low.

The invention discloses a preparation method and application of a TiO2 / Ag-coated MoS2 composite photocatalyst, and relates to the technical field of catalysts.The method comprises the steps that titanium dioxide is evenly dispersed in an ethanol-water mixed solution to form turbid liquid; adding a silver nitrate solution and carrying out ultraviolet irradiation to carry out a photodeposition process; adding an ammonium tetrathiomolybdate precursor solution into the turbid liquid, carrying out ultraviolet irradiation, inducing MoS < 2-> to be subjected to an auto-oxidation reduction reaction through an electronic effect, generating an amorphous MoS2 shell on the surface of silver, and forming a core-shell Ag-coated MoS2 cocatalyst; and centrifuging, washing and drying to obtain the TiO2 / Ag-coated MoS2 composite photocatalyst. According to the Ag-coated MoS2 cocatalyst, the electron density of S atoms is higher, the strength of S (2 + delta)-Had bonds is weakened, and Had is more easily desorbed to form hydrogen; and the photocatalyst also has better light absorption and photo-generated charge separation efficiency, so that the photocatalyst shows better photocatalytic hydrogen evolution activity and stability.

The invention provides nano silver powder as well as a preparation method and application thereof. The preparation method of the nano silver powder comprises the steps that a reducing agent, a pH regulator, a first dispersing agent and a first part of water are subjected to first mixing, a reducing solution is obtained, and the temperature of the reducing solution is controlled to be 0-20 DEG C; silver nitrate, a second dispersing agent and a second part of water are subjected to second mixing, an oxidizing solution is obtained, the temperature is adjusted to-5 DEG C to-20 DEG C, and an oxidizing solid is obtained; and thirdly, under the conditions that the temperature is 0-20 DEG C and the speed is 10-200 rpm, the oxidizing solid and the reducing solution are subjected to third mixing, and the nanometer silver powder is obtained. By changing the state of the materials, solidifying the oxidation system containing the silver salt into the ice crystals and mixing the ice crystals with the reduction system at low temperature, the characteristic that the materials are converted from the solid state to the liquid state is utilized, the production cost of the nano-silver powder is remarkably reduced, the yield and purity of the nano-silver powder are improved, operation is easy, control is convenient, and the method is suitable for industrial production. The method is suitable for industrial large-scale production.

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 belongs to the technical field of photocatalytic materials, and particularly discloses a phosphate radical and carbon doped Z-type photocatalytic material and a preparation method and application thereof.The preparation method comprises the following steps that LCN is prepared, specifically, Chinese redbud tree dead leaf powder and urea are fully mixed and then placed in a muffle furnace to be calcined, and LCN is obtained; the preparation of LCN / Ag3PO4 comprises the following steps: putting LCN into ultrapure water, adding silver nitrate, dropwise adding a Na3PO4 solution, stirring in a dark place, carrying out suction filtration and washing on the material, and finally carrying out freeze drying and collection to obtain the LCN / Ag3PO4. According to the phosphate radical and carbon doped Z-type photocatalytic material as well as the preparation method and the application thereof, ordered transmission of electrons on the interface of the Z-type composite material is induced through dual driving force formed by a carbon intermediate energy level and PO4 < 3->, so that the migration and separation efficiency of generated carriers can be remarkably improved, and the photocatalytic performance of the photocatalytic material is improved. And a certain theoretical support and experimental basis are provided for preparing a high-efficiency heterojunction photocatalytic material.

The invention discloses a 6N high-purity silver raw material for a target material and a preparation method thereof.The preparation method of the 6N high-purity silver raw material for the target material comprises the following steps that 4.5 N silver is placed in a vacuum intermediate frequency furnace to be smelted, and an anode plate is prepared; silver nitrate is purified through a crystallization method and a silver oxide purification method, and high-purity silver nitrate is obtained; the anode plate is loaded into a ceramic membrane, the high-purity silver nitrate is taken to be prepared into an electrolysis mother solution, then the anode plate loaded into the ceramic membrane serves as an anode, titanium-coated silver serves as a cathode, the electrolysis mother solution serves as an electrolyte, and electrolysis is conducted to prepare high-purity silver powder; and the high-purity silver powder is placed in a graphite crucible to be subjected to vacuum melting and then poured into a graphite mold, and the 6N high-purity silver raw material for the target material is prepared. According to the 6N high-purity silver raw material for the target material and the preparation method of the 6N high-purity silver raw material, the purity and stability of the 6N high-purity silver raw material are improved on the basis of guaranteeing the purity of the 6N high-purity silver raw material through combination of various modes such as raw material optimization, equipment optimization and process step improvement.

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 Raman probe-based detection method, which comprises: taking a reducing agent and an alkaline solution, mixing the reducing agent and the alkaline solution to obtain a first solution, and storing the first solution in a first storage device; preparing a second solution and storing the second solution in a second storage device, wherein the second solution comprises a nanoparticle solution and a silver nitrate solution; when a to-be-detected substance is detected, taking out the second solution from the second storage device, then taking out the first solution from the first storage device, and sequentially adding the second solution and the first solution into the to-be-detected substance to obtain a to-be-detected product; and performing Raman signal detection and data analysis on the to-be-detected product. The preparation of the first solution, the preparation of the second solution, the reaction of the second solution and the to-be-detected substance and the reaction of the first solution and the to-be-detected substance are not limited by the laboratory environment, so that the detection threshold of the Raman probe can be reduced, the detection efficiency can be improved, batch detection is realized, and the detection cost is reduced. The requirements on rapid detection of the to-be-detected substance in actual production and life are met.

The invention discloses a preparation method of a full-spectrum response plasmon photocatalyst for reducing carbon dioxide to prepare methane, and belongs to the technical field of photocatalytic reduction of CO2. Tungsten hexacarbonyl and silver nitrate, nickel chloride or chloroauric acid are used as raw materials, and a solvothermal reaction is performed to obtain a plasmon W18O49 nanowire photocatalyst doped with different metal ions. According to the preparation method for preparing the CH4 plasmon photocatalyst through full-spectrum response CO2 reduction, the prepared Au, Ag or N metal ion doped plasmon W18O49 nanowires have high ultraviolet-visible-near infrared light absorption capacity and rich surface oxygen vacancy concentration, adsorption and activation of CO2 molecules are facilitated, meanwhile, the surface oxygen vacancy concentration is increased, and meanwhile, the surface oxygen vacancy concentration is increased. The surface of the catalyst can effectively stabilize a * CO intermediate generated in the photocatalytic CO2 reduction process, and the performance and selectivity of the original plasmon W18O49 for preparing CH4 through photocatalytic CO2 reduction are remarkably 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 discloses a strong hydrophobic silver-loaded visible light response sterilization powder. The preparation method comprises the following steps: 1) fully dispersing g-C3N4 nanosheets in deionized water under an ultrasonic condition to obtain a suspension, adding a silver nitrate aqueous solution into the suspension, adding methanol as a sacrificial agent, and irradiating and stirring by using a xenon lamp to obtain silver-loaded carbon nitride nanoparticles; 2) mixing vinyl-terminated polydimethylsiloxane and toluene, adding the silver-loaded carbon nitride nanoparticles, fully stirring under water bath heating, and then fully stirring by using full light irradiation in an air-isolated environment; 3) dispersing the carbon nitride nano-particles obtained in the step 2) in toluene for centrifugation, removing unloaded vinyl-terminated polydimethylsiloxane, dispersing the centrifuged carbon nitride nano-particles in ethanol, and drying the centrifuged carbon nitride nano-particles. The sterilization powder has good hydrophobicity, and has a broad-spectrum sterilization effect under visible light illumination.

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.