675 results about "Thiourea" patented technology

The invention discloses an application of a molybdenum disulfide-based piezoelectric catalytic material in a seawater uranium extraction material, and relates to the technical field of seawater uranium extraction, thiourea and sodium molybdate are used as precursors, and a MoS2 nanoflower with a specific 1T / 2H composite crystal structure is constructed through a hydrothermal synthesis technology. The method is placed in a uranyl nitrate solution, ultrasonic treatment is combined, efficient extraction of uranium can be achieved, and the method has potential application to extraction of uranium from seawater. The method is simple in process and environment-friendly, almost does not generate harmful waste in the synthesis process, does not need complex operation, and has good amplification preparation potential.

The invention discloses a preparation method of a 3-micron ultrathin lithium battery copper foil. The preparation method comprises the following steps: preparing a copper sulfate electrolyte; a wetting agent, a brightening agent and a high resistance agent are added into the copper sulfate electrolyte, the high resistance agent is at least one of thiazolidinethione, polyethyleneimine, 2-mercaptobenzimidazole and ethylene thiourea, and a mixed additive is formed; polishing and grinding a cathode roller by adopting a flying wing wheel, and carrying out electrolytic treatment on the mixed additive through the polished and ground cathode roller to obtain a first-stage copper foil; and the first-stage copper foil is placed in a nitrogen furnace to be subjected to annealing treatment, and the 3-micron ultrathin lithium battery copper foil is obtained. The invention aims to solve the technical problems that in the prior art, edge tearing, foil breaking, warping, dark appearance oxidation and the like are prone to occurring in the production process of the ultrathin copper foil, the tensile strength and the ductility are difficult to consider at the same time, and stable mass production of the 3-micron copper foil is still difficult.

The invention relates to the technical field of precious metal recovery, in particular to a process for separating precious metal from copper-nickel smelting waste, which comprises the following steps: crushing and grading the waste, adding a sulfuric acid solution containing etidronic acid, leaching, and washing, drying and crushing filter residues to obtain a pretreated material; mixing the pretreated material with a sodium peroxide-sodium carbonate composite flux, roasting, leaching with water, and filtering to obtain a filter residue B; adding a leaching agent containing hydrochloric acid, sodium chlorate and 1, 2-cyclohexanediamine tetraacetic acid into the filter residue B according to the ratio of 1: 3-1: 5, and filtering to obtain filtrate C and filter residue C; adjusting the pH value of the filtrate C to 1.5-2.5, adding an ethanol solution of sodium N, N-diethyldithiocarbamate, precipitating, washing and calcining to obtain sponge palladium; adding ammonium chloride into the filtrate D, precipitating and calcining to obtain sponge platinum; and leaching the filter residue C by using a hydrochloric acid-chloroauric acid mixed solution containing diphenylthiourea, and replacing and calcining zinc powder to obtain crude gold. According to the process, the leaching rates of platinum, palladium and gold and the product purity are greatly improved; flux and reagent systems are optimized, consumption and energy consumption are reduced, waste liquid treatment is matched for up-to-standard discharge, and efficient resource recovery and environment-friendly cooperation are achieved.

The invention discloses a method for preparing a sulfur-doped nickel hydroxide-based self-supporting electrolyzed water anode, and belongs to the technical field of preparation of electrolyzed water catalytic electrodes, and the method comprises the following steps: S1, preparing strong oxidizing salt, thiourea and transition metal salt into an active solution; s2, pretreating the nickel-containing metal substrate to obtain a precursor; and S3, immersing the precursor in an active solution for ultrasonic impregnation, and performing in-situ oxidation to prepare the sulfur-doped nickel hydroxide-based self-supporting electrolytic water anode. According to the method for preparing the sulfur-doped nickel hydroxide-based self-supporting electrolytic water anode, an oxidizing agent-thiourea-transition metal salt synergistic reaction system is adopted, an ultrasonic-assisted technology is combined, and a high-performance catalytic layer is directly grown on the surface of the metal substrate in situ at room temperature; the invention aims to synchronously realize high catalytic activity, excellent stability and macro preparation of the electrode and fundamentally solve the core pain points of long process, high energy consumption, difficulty in amplification and the like in the prior art.

The invention discloses asphalt-based hard carbon, a preparation method thereof and a sodium-ion battery negative electrode material, and relates to the technical field of sodium-ion batteries. The preparation method of the asphalt-based hard carbon comprises the following steps: S1, mixing an asphalt precursor, a sulfur source and a cross-linking agent, and performing cross-linking vulcanization treatment at a first temperature to obtain a primary product; s2, performing carbonization treatment on the primary product at a second temperature to obtain asphalt-based hard carbon; the sulfur source is any one of elemental sulfur, thiourea, dimethyl sulfide and sulfide, or any two of elemental sulfur, concentrated sulfuric acid, thiourea, dimethyl sulfide and sulfide. By adopting the method, the type of the sulfur source is controlled, and the sulfur source and the cross-linking agent are added, so that the reversible capacity and the rate capability of the asphalt-based negative electrode material can be effectively improved, and the application field of the asphalt-based negative electrode material is widened.

The invention discloses a method for separating and recovering selenium and mercury from acid mud containing selenium and mercury. The method comprises the following steps: mixing the acid mud containing selenium and mercury with water, performing wet ball milling, filtering and drying to obtain a ball milling material; adding a hydrogen peroxide solution into the ball-milled material, adding hydrochloric acid to adjust the acidity, carrying out oxidation acid leaching, and carrying out solid-liquid separation to obtain selenium-containing mercury liquid and selenium-removed mercury slag; adding thiourea into the selenium-containing mercury liquid for selective reduction, and performing solid-liquid separation to obtain crude selenium and reduction liquid; zinc powder is added into the reduction liquid for mercury replacement and precipitation, and crude mercury and precipitation liquid are obtained after solid-liquid separation; wherein the selenium-removed mercury slag and the precipitation solution are subjected to centralized treatment. The method is simple in process, convenient to operate and easy to process, selenium and mercury in the acid mud containing selenium and mercury can be removed at a time, efficient separation and recovery of selenium and mercury in the acid mud containing selenium and mercury are achieved, harmless treatment of hazardous waste and effective utilization of resources are achieved, and the method conforms to the concept of green sustainable development.

The invention discloses a preparation method of modified salicornia biochar, and belongs to the technical field of environmental protection. The preparation method comprises the following steps: washing, drying and crushing salicornia europaea serving as a raw material, mixing the salicornia europaea with a nitrogen source modifier according to a certain mass ratio, adding water, uniformly stirring, dipping and drying; the nitrogen source modifier is one or more of urea, melamine or thiourea; then carrying out pyrolysis and carbonization, grinding, washing and drying the obtained carbon material, and finally preparing the modified salicornia biochar. The prepared modified salicornia biochar is used for adsorbing organic matters in sewage or wastewater, can effectively remove dissolved organic carbon (DOC, 86.34%), UV254 (89.33%) and chromaticity (CN, 94.74%) in an adsorption experiment of livestock and poultry biogas slurry, and shows excellent adsorption performance. The method follows the principle of treating waste with waste, the salicornia europaea waste is effectively treated, the obtained biochar has good application potential in the aspect of sewage and wastewater treatment, and high-value utilization of the waste is achieved.

The invention relates to the technical field of nano-catalysts, and discloses a preparation method and application of a ZnxCd1-xS nano-catalyst rich in sulfur vacancies, the preparation method of the ZnxCd1-xS nano-catalyst rich in sulfur vacancies is characterized by comprising the following steps: S1, mixing cadmium salt, zinc salt and thiourea in deionized water to obtain a mixed solution; and S2, putting the mixed solution into a reaction kettle for heating reaction, cooling, collecting a reaction product, washing the reaction product with deionized water, and drying the washed reaction product to prepare the ZnxCd1-xS nano-catalyst. The ZnxCd1-xS nano-catalyst synthesized by the method is uniform in dispersion, uniform in size and regular in morphology, the morphology of the obtained ZnxCd1-xS nano-catalyst is evolved into a litchi-shaped transition state with a rough surface from a spherical shape along with the rise of the reaction temperature, and then a pine tree-shaped morphology with the regular morphology is generated. In addition, the prepared catalyst is rich in certain sulfur vacancies, and the performance is remarkably improved when the catalyst is applied to the field of photocatalytic hydrogen evolution.

The invention relates to the technical field of photocatalysts, in particular to a bismuth-defect bismuth oxybromide-sulfur-defect bismuth sulfide bromide heterojunction and a preparation method and application thereof in photocatalytic CO2 reduction, Bi (NO3) 3.5 H2O, thiourea, cetyltrimethylammonium bromide (CTAB) and the like are used as raw materials, and the VBi-Bi4O5Br2 / VS-Bi19Br3S27 heterojunction is prepared through a two-step hydrothermal method. According to the VBi-Bi4O5Br2 / VS-Bi19Br3S27 heterojunction, bismuth vacancies and sulfur vacancies are introduced, the visible light absorption range of the material is expanded through a proper amount of double vacancies, more electron capture centers are provided, and the separation efficiency of photo-induced electrons and the vacancies is improved, so that the VBi-Bi4O5Br2 / VS-Bi19Br3S27 heterojunction has excellent performance of photocatalytic reduction of CO2, and the preparation method of the VBi-Bi4O5Br2 / VS-Bi19Br3S27 heterojunction is suitable for large-scale production and application of the VBi-Bi4O5Br2 / VS-Bi19Br3S27 heterojunction. CO2 can be reduced into a single product CO, and the photoreduction efficiency of the carbon dioxide can be improved.

The invention discloses a low-cost nano porous silicon-carbon composite material based on a solid waste silicon source as well as a preparation method and application thereof. The preparation method comprises the following steps: taking a solid raw material containing silicon dioxide as a silicon source; carrying out wet ball milling on the pretreated raw materials; mixing the ball-milled material with magnesium powder, aluminum chloride and lithium chloride; carrying out heating reduction reaction on the mixed material; sequentially performing hydrochloric acid pickling and hydrofluoric acid pickling on the reduction product, and then washing to be neutral; mixing the washed silicon particles with a carbon precursor containing nitrogen and sulfur, coating by adopting a spray coating method, and then carrying out carbonization treatment; the carbon precursor containing nitrogen and sulfur is composed of asphalt and thiourea; the carbonization temperature is 750-850 DEG C, the carbonization time is 1-2 hours, and the heating procedure comprises a desolventizing section, an asphalt decomposition section and a carbonization section. The preparation method is low in raw material cost, low in energy consumption, environment-friendly and excellent in product comprehensive performance, and has wide application prospects in the fields of power batteries, energy storage, catalysis and the like.

The invention relates to the technical field of immunochromatography analysis, and discloses a signal enhancer of a colloidal gold immunochromatography rapid detection card and a preparation method thereof, the signal enhancer comprises a silver ion solution, a thiourea-ascorbic acid synergistic reducing agent, a pH buffer system and a surfactant stabilizing system, the signal amplification is realized by catalyzing and depositing silver nanoparticles on the surface of colloidal gold, the operation is simple and convenient, one-time addition is realized, and the reaction is completed within 5-10 minutes; the sensitivity is improved by 5-10 times, and the specificity is higher than 98%; the stability is excellent, and the storage time is 12 months at 4 DEG C; various colloidal gold rapid detection cards are universally compatible; compared with the prior art, the colloidal gold immunochromatography rapid detection card has the advantages that the cost is controllable, the single detection is increased by 0.3-0.5 yuan, and the colloidal gold immunochromatography rapid detection card is particularly suitable for ultra-sensitive detection of small molecular substances in the field of food safety, for example, the detection limit of malachite green reaches 0.1 microgram per liter, the detection limit of fipronil reaches 0.5 microgram per liter, and the application range of the colloidal gold immunochromatography rapid detection card is obviously expanded.

The invention relates to the technical field of etching solutions, and discloses a molybdenum-aluminum-niobium etching solution for a TFT-LCD (Thin Film Transistor Liquid Crystal Display), which comprises the following components in percentage by mass: 50 to 60 percent of phosphoric acid, 3 to 8 percent of nitric acid, 5 to 10 percent of glacial acetic acid, 1 to 5 percent of aluminum nitrate, 0.1 to 0.5 percent of diphenyl thiourea, 1 to 5 percent of etidronic acid, 3.0 to 5.0 percent of sodium hexametaphosphate, 0.1 to 0.2 percent of fatty alcohol-polyoxyethylene ether, 0.5 to 0.8 percent of amino trimethylene phosphonic acid and the balance of ultrapure water. The invention further discloses a preparation method of the molybdenum-aluminum-niobium etching solution. According to the invention, a phosphorus nitrate vinegar system, a composite additive, a novel corrosion inhibitor, a metal ion chelating agent and a surfactant matched with the etching liquid are adopted, so that the molybdenum-aluminum-niobium multi-layer composite metal film can be simultaneously etched at one time; the etching solution has the advantages of being uniform in etching, capable of inhibiting Mo / Nb etching, high in selectivity, controllable in etching rate, free of residues, long in service life, high in stability and the like.

The invention discloses a thiochromanone derivative containing a thiosemicarbazone structure and application of the thiochromanone derivative, relates to the technical field of medicines, and particularly relates to the technical field that the compound has better oxidation resistance and alpha-glucosidase resistance activity, the IC50 value of the compound 1-(7-chloro-4, 4-dioxothiochromanone-3-N-propyl) thiosemicarbazone to ABTS clearance activity is 2.86 [mu] g / mL, the IC50 value of the compound 1-(7-chloro-4, 4-dioxothiochromanone-3-N-propyl) thiosemicarbazone to alpha-glucosidase inhibition activity is 9.51 [mu] g / mL, and the effect is the best and is superior to that of a control agent vitamin E and acarbose. The thiochromanone derivative containing the thiosemicarbazone structure has a general formula shown in the specification,

The application discloses a method for synthesizing a single-atom catalyst, which comprises the following steps of mixing raw materials: taking dimethyl imidazole, zinc nitrate and graphene oxide as solutes, and taking anhydrous methanol as a solvent to form ZIF-8@GO through stirring; taking ZIF-8@GO and thiourea as solutes, and taking anhydrous methanol as a solvent to form S / ZIF-8@GO through stirring and adsorption; first-stage pyrolysis: pyrolyzing S / ZIF-8@GO in a protective gas atmosphere to form porous carbon (S, N-C); precursor preparation: after the porous carbon is cooled, phenanthroline (Phen) and a transition metal source (M) are added into the porous carbon to form a precursor M / S, N-C@Phen; and second-stage pyrolysis: pyrolyzing the M / S, N-C@Phen precursor in a protective gas atmosphere to obtain a M / S, N-C single-atom catalyst. The synthesis method is simple and effective, can be used for large-scale synthesis of a single-atom catalyst, is suitable for synthesis of various metal single-atom catalysts, and solves the problems of complexity in the prior art and difficulty in large-scale preparation.

The invention discloses a stepped recovery method for key components of a core layer laminated structure of a waste photovoltaic module, which comprises the following steps: crushing and pyrolyzing the core layer laminated structure of the waste photovoltaic module to obtain granular powder, and sequentially carrying out selective aluminum leaching and aluminum recovery treatment by using a composite organic acid solution, the step-by-step recovery of key components such as aluminum, silver, lead and silicon elements is realized through selective silver-lead leaching and silver recovery treatment of a thiourea composite complexing oxidation solution, precipitation and solidification treatment of lead and purification and recovery treatment of silicon. According to the recycling method, selective separation and efficient recycling of corresponding metal and silicon resources are carried out on the composite waste containing a silicon substrate (containing an antireflection layer SiNx and SiO2), silver, aluminum, EVA and PbO according to the gradient separation sequence of aluminum, silver, lead and silicon.

The invention discloses an online monitoring and regulating system for inhibiting nitration reaction by thiourea for sewage treatment, and relates to the technical field of sewage treatment. Comprising an on-line monitoring module which monitors and obtains nitrification parameters and environmental parameters in the nitrification activity process through an on-line analyzer and a sensor network, and adjusts parameter monitoring frequency according to the nitrification parameters; the intelligent control module is used for determining optimal parameters of a PID (Proportion Integration Differentiation) controller through a virtual reference model according to the nitrification parameters and the environmental parameters, and determining the addition amount of a thiourea solution according to the optimal parameters; and the thiourea adding unit is used for adding the thiourea solution at an adding point through adding equipment according to the adding amount of the thiourea solution. According to the method, excessive inhibition possibly caused by a traditional control model based on historical data is avoided, the risk that fragile nitrifying flora is thoroughly killed is effectively prevented, success of the bacterium cultivation process is ensured, and the system starting time is shortened.

The invention belongs to the technical field of talc, and provides a method for detecting fluorescent substances in talc raw ore, which comprises the following steps: S1, carrying out ball milling on the talc raw ore in a ball mill, sieving to obtain sieved powder, and adding deionized water into the sieved powder to obtain slurry; s2, adding the slurry into the mixture to enable the pH value of the slurry to be 5, stirring, and standing in a water bath for 2-3 hours to obtain a first precipitate; s3, adding a thiourea-ascorbic acid solution into the first precipitate to obtain a second precipitate; and S4, carrying out secondary ball milling on the second precipitate, and spreading the second precipitate in an enamel plate to detect whether the talc raw ore contains the fluorescent substances or not. The hydrochloric acid can dissolve quartz and mica to avoid generation of background fluorescence or quenching effect, and the nonionic surfactant polyethylene glycol can be adsorbed on the surface of the mineral to reduce interfacial tension, so that the hydrochloric acid is easier to infiltrate tiny pores, the pit defect caused by local over-corrosion is reduced, the pickling uniformity is improved, and the detection sensitivity is improved.

The invention discloses a synthesis method of an oxazole derivative, and belongs to the technical field of chemical synthesis. The oxazole derivative is synthesized from a ketone ester compound and thiourea through a one-pot method, the required raw materials are cheap and easy to obtain, the experimental operation is simple, the reaction condition is mild, a metal catalyst and other reagents are not needed, and the defects that a metal catalysis synthesis method is used, for example, the catalyst is high in price, the reaction synthesis route steps are many, and the synthesis cost is low are overcome. The method has the advantages of mild reaction conditions, low reaction rate, unstable intermediate, low yield and the like, bypasses most complex synthesis steps of a metal-free catalytic synthesis method, and develops a simple, efficient, green and environment-friendly way for synthesizing the oxazole derivative. Under mild conditions, ketone ester substrates with different substituent groups have very strong compatibility, and a new green synthesis way is provided for synthesis of substituted oxazole.

The invention provides a preparation method of a magnetic recoverable catalyst and a method for synthesizing 3-mercaptopropionic acid, and mainly solves the problem that a large amount of acid and alkali solutions are needed in the existing acrylonitrile-sodium hydrosulfide and acrylic acid-thiourea process routes. The thiohydracrylic acid synthesis catalyst is prepared. The use conditions of the catalyst are as follows: the temperature is 30-80 DEG C, the reaction pressure is 0.5-3 MPa, the mass ratio of the acrylic acid to the solvent is 0.1-5, and the mass ratio of the acrylic acid to the catalyst is 0.2-20. Compared with the prior art, the catalyst disclosed by the invention is used as a synthetic catalyst for preparing thiohydracrylic acid through reaction of acrylic acid and hydrogen sulfide, a solid catalyst and a liquid reaction system can be completely separated by adopting simple methods such as filtration, centrifugation or magnetic separation, and a complicated pickling step is not needed; and the problem that a homogeneous catalyst is difficult to rectify after salification in the use process is avoided.

The application belongs to the field of organic synthesis and particularly relates to a synthesis method of polysubstituted indole propionate derivatives. Aryl acetate compounds and sulfonyl indole compounds are used as raw materials, and the reaction is carried out through an isothiourea organic small molecule catalyst. The reaction raw materials are simple and easy to obtain, the reaction conditions are mild, the operation is simple, the reaction time is short, the reaction has good diastereoselectivity and high yield, the synthesis method of the polysubstituted indole propionate derivatives overcomes the defects and deficiencies of the existing synthesis method, and has the characteristics of high efficiency, simplicity and wide universality.

The invention discloses a synthesis method of 5-(1H-pyrrole-1-yl)-2-mercaptobenzimidazole, which comprises the following steps: carrying out cyclization condensation reaction on o-phenylenediamine and thiourea in an acidic environment provided by hydrochloric acid to obtain 2-mercaptobenzimidazole; the preparation method comprises the following steps: carrying out nitration reaction on 2-mercaptobenzimidazole, sulfuric acid and nitric acid to obtain 2-mercapto-5-nitrobenzimidazole; the preparation method comprises the following steps: carrying out nitro reduction reaction on 2-sulfydryl-5-nitrobenzimidazole and hydrogen under the catalysis of nickel to obtain 5-amino-2-sulfydryl benzimidazole; the preparation method comprises the following steps: carrying out an N-alkylation reaction on 5-amino-2-mercapto benzimidazole and tetrahydro-2, 5-dimethoxyfuran under the catalysis of copper chloride to generate 5-(1H-pyrrole-1-yl)-2-mercapto benzimidazole, and carrying out a reaction on the 5-amino-2-mercapto benzimidazole and tetrahydro-2, 5-dimethoxyfuran to generate the 5-(1H-pyrrole-1-yl)-2-mercapto benzimidazole. The method disclosed by the invention has the outstanding advantages of mild and easily-controlled conditions, simple and convenient post-treatment, high yield, economy, environmental protection, suitability for large-scale production and the like, conforms to the green chemical development concept, and has important application value.

This invention discloses a method for determining the arsenic content in ores, belonging to the field of ore element detection technology, comprising the following steps: (1) weighing the ore sample, adding hydrochloric acid-nitric acid mixed acid for acid hydrolysis, then adding hydrofluoric acid and perchloric acid for auxiliary digestion, evaporating to near dryness, and dissolving the residue with hydrochloric acid; (2) adding a thiourea-ascorbic acid-citric acid mixed reducing masking agent to reduce and mask interfering ions; (3) using an atomic fluorescence spectrometer to determine the fluorescence intensity of arsenic in the sample solution, and calculating the arsenic content according to the standard curve. This method achieves accurate and stable determination of arsenic in various ores such as phosphate rock and iron ore by optimizing sample pretreatment conditions, improving the reduction system and matrix interference suppression strategy.

This invention discloses an acetic acid-modified inorganic composite gel material and its preparation method, belonging to the field of organic material synthesis technology. The acetic acid-modified inorganic composite gel material comprises the following materials in parts by weight: 0.2-0.4 parts of acetic acid-Co3O4, 1.5-2.5 parts of acrylamide, 1-1.5 parts of glycerol, 0.05-0.1 parts of N-N-dimethylformamide, 0.25-0.5 parts of ammonium persulfate, 0.1-0.15 parts of sulfonated-Bi2O3, 0.6-0.9 parts of ethylenediamine, and 0.2-0.4 parts of PVP; the acetic acid-Co3O4 comprises materials in the following mass ratio: acetic acid:cobalt nitrate:thiourea:ammonium fluoride:sodium bicarbonate = 3-7:1.5-2.5:0.8-1.2:0.5-1:6; the sulfonated-Bi2O3 comprises materials in the following mass ratio: Bi2O3:sodium sulfite:H2O2:ammonium bicarbonate = 3-5:0.2-0.6:1-1.5:1. This material achieves efficient and stable catalysis for nitrogen reduction under mild conditions through structural defect regulation, interfacial functional group modification, heterojunction electronic regulation, and synergistic enhancement with organic gel.

The invention relates to the technical field of zinc hydrometallurgy, and discloses an analysis method for measuring high cobalt content by an EDTA complexing back titration method, which is based on the following steps: oxidizing Co < 2 + > into Co < 3 + > by using potassium nitrite in an acetic acid medium to form cobalt potassium nitrite precipitate so as to realize separation of cobalt and interfering ions, dissolving the precipitate, complexing with excessive EDTA, and performing back titration by using a zinc standard solution. Xylenol orange is used as an indicator, and determination is completed at room temperature in a hexamethylenetetramine buffer system with the pH value being approximately equal to 5.8. Coexisting ion interference is effectively eliminated through tartaric acid, sodium fluoride, thiourea and other masking agents, the method has the advantages of being easy and convenient to operate, sensitive in end point, high in accuracy and low in cost, and the requirement for conventional analysis of high-cobalt materials can be met.

The invention relates to the technical field of detection, and particularly provides a method for determining the quality and purity of silver in a silver-gold-plated product. The determination method comprises the following steps: dissolving a surface gold plating layer of a silver-plated product with aqua regia, and then dissolving a silver chloride protective film on the surface of silver with ammonia water, so that the problem that the mass of silver cannot be accurately weighed after the gold plating layer in the product is removed is solved, and the problem that the silver chloride protective film hinders the dissolution of pure silver with nitric acid to influence the determination is also solved. Thiourea is further adopted to dissolve a complex of diamine and silver, the situation that when silver is dissolved, added nitric acid reacts with the complex of diamine and silver to generate silver chloride precipitates is prevented, an ammonium nitrate solution is used for washing thiourea, a flame atomic absorption spectrometry method is adopted for conducting mass correction on silver in the solution obtained after aqua regia gold is dissolved, and the total silver mass is obtained through calculation. According to the determination method, the quality and the purity of the silver in the silver-plated product can be relatively accurately obtained.

The invention discloses a preparation method of FePS3, which comprises the following steps: mechanically mixing pyrite powder, sulfur-containing small molecules and elemental phosphorus, calcining the fully mixed powder in two temperature stages under a protective atmosphere, and cooling to obtain FePS3 nano-powder; wherein in the first temperature stage, the temperature is 200-300 DEG C, and the heat preservation time is 120-240 minutes, and in the second temperature stage, the temperature is 400-600 DEG C, and the heat preservation time is 120-180 minutes; the sulfur-containing small molecules are thiourea, thioacetamide or a mixture of the thiourea and the thioacetamide; the molar ratio of sulfur atoms to phosphorus atoms in FeS2 molecules and sulfur-containing small molecules in the pyrite powder is (1: 3: 5)-(1: 1: 5). According to the method, pyrite is used as an iron source and a sulfur source, sulfur-containing small molecules are used as a second sulfur source, and the FePS3 nano-powder is directly obtained through solid-phase reaction with the simple substance phosphorus without additional purification treatment. The method is low in solid-phase reaction temperature and simple in process, does not need harsh reaction conditions, and is easy for large-scale production.

Provided are a test reagent that reduces non-specific adsorption and is capable of detecting a low-concentration target substance, and a detection method including using the test reagent. The test reagent is a test reagent for in vitro diagnosis, and comprises: a thiourea compound; and resin particles, wherein the resin particles each have a sulfur element.

The application discloses a method for preparing a composite sulfur-based catalyst from waste nickel-cobalt-manganese ternary material and application thereof, and belongs to the field of lithium-oxygen battery catalysts. The method comprises the following steps: (1) dispersing waste ternary positive electrode powder in an aqueous solution of an organic acid to obtain a dispersion liquid, heating, adding an aqueous hydrogen peroxide solution, stirring, and performing suction filtration to obtain a leaching solution; (2) mixing thiourea, a surfactant and the leaching solution to obtain a reaction liquid; and (3) placing the reaction liquid and carbon cloth in a sealed container, reacting, cleaning, and drying to obtain a composite sulfur-based catalyst. The composite sulfide of the three transition metals (Ni, Co and Mn) recovered by the method has a catalytic effect on the charging process of a lithium-oxygen battery, and can greatly improve energy efficiency.

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 kind of iron monatomic catalysts with controllable sulfur content and coordination mode and its preparation method and application, nitrogen-allyl thiourea and thiocyanic acid are respectively used as sulfur-containing organic ligand and sulfur-containing supramolecular precursor, chelate with iron ion, and use the hydrogen bond interaction between melamine and cyanuric acid, complete supramolecular self-assembly process;And high-temperature pyrolysis is carried out under argon atmosphere, and iron monatomic catalysts with controllable sulfur content and coordination mode can be prepared.The application also includes the application of iron monatomic catalysts with controllable sulfur content and coordination mode in removing organic pollutants such as p-chlorophenol and antibiotics in water.Iron monatomic catalysts with controllable sulfur content and coordination mode can improve the activation efficiency of persulfate, the content and selectivity of active oxygen species generated, and achieve efficient degradation of p-chlorophenol under different anion-cation, humic acid and pH conditions, while having good recycling performance.