Molecular formula: Sb2S3, molecular weight: 339.68. Pure antimony trioxide is yellow-red amorphous powder with a relative density of 4. 12 and a melting point of 550℃. Insoluble in water and acetic acid, soluble in concentrated hydrochloric acid, alcohol, ammonium sulfide and potassium sulfide solution. Antimony sulfide used in fireworks and firecrackers industry is processed from stibnite powder, which is black or grayish black powder with metallic luster, insoluble in water and strong reducibility.

molybdenum disulfide

Main components of molybdenite. Black solid powder with metallic luster. Chemical formula MoS2, melting point 1 185℃, density 4.80 g/cm3 (14℃), Mohs hardness 1.0 ~ 1.5. 1370℃ began to decompose, and 1600℃ decomposed into molybdenum and sulfur. 3 15℃ is heated in air and begins to be oxidized. When the temperature rises, the oxidation reaction accelerates. Molybdenum disulfide is insoluble in water, but only soluble in aqua regia and boiled concentrated sulfuric acid. The preparation methods of molybdenum disulfide are as follows: ① Molybdenum and sulfur are directly combined. ② Molybdenum trioxide reacts with hydrogen sulfide gas. (3) melting the mixture of molybdenum trioxide, sulfur and potassium carbonate together. Molybdenum disulfide is an important solid lubricant, especially suitable for high temperature and high pressure. It also has diamagnetism, can be used as a linear photoconductor and a semiconductor with P-type or N-type conductivity, and has the functions of rectification and energy conversion. Molybdenum disulfide can also be used as a catalyst for dehydrogenation of complex hydrocarbons.

Also known as "the king of advanced solid lubricants". Molybdenum disulfide is a solid powder made of natural molybdenum concentrate powder by chemical purification and changing its molecular structure. This product is black, slightly silvery gray, with metallic luster, slippery to the touch and soluble in water. The product has the advantages of good dispersibility and non-adhesion, and can be added to various oil products to form a non-adhesion colloidal state, thus increasing the lubricity and extreme pressure of oil products. It is also suitable for high temperature, high pressure, high speed and high load mechanical working conditions, and prolongs the service life of the equipment. The main function of molybdenum disulfide used in friction materials is to reduce friction at low temperature and increase friction at high temperature, with small ignition loss and easy volatilization in friction materials. Friction reduction: the particle size of molybdenum disulfide crushed by supersonic airflow reaches 325-2500 meshes, the particle hardness is 1- 1.5, and the friction coefficient is 0.05-0. 1, which can play a role in friction materials. Increased friction: Molybdenum disulfide is non-conductive, and there are polymers such as Molybdenum disulfide, Molybdenum trisulfide and Molybdenum trioxide. When the temperature of the friction material rises sharply due to friction, the molybdenum trioxide particles in the polymer expand with the increase of temperature, which plays a role in increasing friction; Oxidation resistance: Molybdenum disulfide is obtained by chemical purification and comprehensive reaction, and its PH value is 7-8, which is slightly alkaline. It covers the surface of friction material, which can protect other materials from oxidation, especially make other materials difficult to fall off and enhance adhesion; Fineness: 325 mesh -2500 mesh; Silicon dioxide: 0; PH value: 7-8; Density: 4.8-5.0g/cm3; Hardness:1-1.5; Loss on ignition:18-22%; Friction coefficient: 0.05-0.09.

ferrous sulfide

Ferrous sulfide is a dark brown hexagonal crystal which is insoluble in water. It can be obtained by melting sulfur and iron in a high vacuum sealed tube. The cost of ferrous sulfide prepared in this way as a chemical reagent is higher, while the chemical pure reagent ferrous sulfide has more impurities.

The storage of chemical reagents should be in contact with air even if it is sealed. In the case of trace moisture in the air, ferrous sulfide is gradually oxidized into ferroferric oxide and sulfur. The chemical equation is as follows: 12FeS+8O2 water12s+4f3o4. When ferrous sulfide reacts with dilute hydrochloric acid or dilute sulfuric acid to generate hydrogen sulfide gas, because it is prepared in Cape generator or its simple device, the sulfur in the oxide layer on the solid surface of ferrous sulfide does not react with dilute hydrochloric acid or dilute sulfuric acid, which hinders the contact between ferrous sulfide and hydrogen ions in acidic solution (that is, although ferrous sulfide is insoluble, it can dissolve a little after all, and the dissolved part completely ionizes ferrous ions and sulfur anions). At this time, there are almost no sulfur anions in the solution, and almost no hydrogen sulfide combines with hydrogen ions to form a weak electrolyte. On the other hand, ferroferric oxide reacts slowly with dilute hydrochloric acid and dilute sulfuric acid at room temperature. Dissolving ferroferric oxide will consume more hydrogen ions and reduce the concentration of hydrogen ions. The chemical equation of this reaction is Fe (FeO2) 2+8h+= Fe2+2fE3++4h2o.

The reaction speed is slow and cannot be heated, so hydrogen sulfide gas cannot be generated. The ferrous sulfide solid must be pretreated to remove the oxide layer on the surface.

The oxide layer on the surface of ferrous sulfide can be dissolved by heating with hydrochloric acid of 1∶ 1, so that the ferroferric oxide on the surface can be dissolved into soluble iron salt and ferrous salt, and the adhesion of sulfur attached to the surface of ferrous sulfide is weakened. When the solution boils, sulfur will leave the surface of ferrous sulfide due to the jump of solids. Then the ferrous sulfide solid is taken out and washed to obtain a relatively pure convex-concave ferrous sulfide solid.

Ferrous sulfide with oxide layer removed should not be left for too long, and the oxide layer should be treated the day before the experiment for later use. Storage method: it cannot be stored in reagent bottle because it is easy to oxidize; But it can be tightly wrapped with polyethylene plastic film. In order to prevent the membrane from being damaged, a layer of membrane can be added to prevent it from being oxidized in contact with air.

In the preparation of hydrogen sulfide gas, in order to meet the requirements of demonstration experiments, warm dilute sulfuric acid can react with ferrous sulfide solid in a simple device of Kipp generator (hydrogen chloride gas will be mixed in hydrogen sulfide when hydrogen sulfide is prepared with hydrochloric acid), so that the collected hydrogen sulfide gas can be used for its properties experiments, such as acidity of aqueous solution, reaction with copper sulfate solution, and ignition of hydrogen sulfide.

copper sulphide

Molecular weight: 95.6 1

Melting point: 220℃

Properties: Black-brown amorphous powder or granules. Soluble in dilute nitric acid, hot concentrated hydrochloric acid, sulfuric acid and sodium cyanide solution, slightly soluble in ammonium sulfide solution and insoluble in water and sodium sulfide solution. It can be oxidized to colloidal state in humid air. The conductivity is better than that of cuprous sulfide. Heated to 220℃ and decomposed into cuprous sulfide.

On August 5th, we saw the copper sulfide 14 microcrystals synthesized by scientists in Hefei National Laboratory of Microscale Material Science, China. Its successful discovery indicates that China has made important progress in the research of special microstructure crystal construction, and its potential application prospect lies in that it can be used as a building unit of larger structure and also as a carrier for coating other materials on a micro scale.

The research team led by Professor Yu Shuhong of China University of Science and Technology synthesized copper sulfide 14 polyhedral microcrystals. Professor Yu Shuhong and his collaborators reacted the ethylene glycol solution of copper nitrate with elemental sulfur in a reactor at 140℃ for one day, then collected the black solid by centrifugation, and found this special microstructure material by scanning electron microscope.

stannic sulfide

Density 4.5

Character; Role; letter

Yellow hexagonal sheet.

Dissolution situation

Soluble in aqua regia and hot alkali solution, insoluble in water, hydrochloric acid and nitric acid.

use

Used for imitation gold electroplating and pigment production.

Preparation or source

It can be prepared by the action of sulfide on tin chloride solution.

other

Decomposition at 600℃.

manganese sulfide

As an important magnetic semiconductor, nano-manganese sulfide has potential application value in short-wavelength photoelectric devices.

The purpose of this thesis is to explore hydrothermal and solvothermal methods to synthesize nano-MnS with regular morphology. According to the synthetic route designed before the experiment, nano-MnS was prepared by hydrothermal/solvothermal method. The crystal form of synthesized nano MnS was analyzed by X-ray diffractometer, and the morphology of the product was analyzed by scanning electron microscope. The formation mechanism under hydrothermal and solvothermal conditions was preliminarily discussed.

The effects of experimental parameters such as sulfur source, solvent and reaction temperature on the crystal form and morphology of MnS synthesized by hydrothermal/solvothermal method were studied. According to the test results, at the same temperature, when thiourea is used as sulfur source, the products tend to form stable α phase, while the products prepared with sodium thiosulfate as sulfur source have both α phase and metastable γ phase. The pyramid products prepared with thiourea as sulfur source have better morphology than those prepared with sodium thiosulfate as sulfur source. The products produced by using water as solvent are pyramids, while those produced by using ethylene glycol as solvent are rod-shaped or rod-shaped flowers. Ethylene glycol as solvent is beneficial to the synthesis of metastable phases β and γ-MnS, and water as solvent generates α-MnS. The increase of temperature not only makes the product grow better, but also makes the product change from β and γ-MnS to α-MnS.

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