Cobalt(II) selenide is an inorganic compound with the

chemical formula In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbol ...

CoSe. The mineral form of this compound is known as freboldite. Similar minerals include trogtalite (CoSe₂) and bornhardtite (Co²⁺Co³⁺₂Se₄).

Preparation

Cobalt(II) selenide can be prepared by placing cobalt selenite in 10% sodium hydroxide solution, stirring it, and adding it drop by drop into the 10% sodium hydroxide solution of

sodium thiosulfate Sodium thiosulfate (sodium thiosulphate) is an inorganic compound with the formula . Typically it is available as the white or colorless pentahydrate, . The solid is an efflorescent (loses water readily) crystalline substance that dissolves well in ...

. When the color of the reaction solution no longer changes, let it stand, filter, and use water and wash it with 5% hydrochloric acid and dry it to obtain CoSe.朱文祥. 无机化合物制备手册. 化学工业出版社, 2006. pp 653-654. 【IX-20】硒化钴. ISBN 7-5025-8537-0 Cobalt(II) selenide can also be produced by the electrodeposition reaction of

cobalt(II) acetate Cobalt(II) acetate is the cobalt salt of acetic acid. It is commonly found as the tetrahydrate Co(CH3CO2)2·4 H2O, abbreviated Co(OAc)2·4 H2O. It is used as a catalyst. Synthesis and structure Like many other transition metal acetates, cobalt(I ...

and

sodium selenite Sodium selenite is the inorganic compound with the formula Na2SeO3. This salt is a colourless solid. The pentahydrate Na2SeO3(H2O)5 is the most common water-soluble selenium compound. Synthesis and fundamental reactions Sodium selenite usually i ...

in acidic solution. When the pH is 3.5, the ratio of

cobalt Cobalt is a chemical element with the symbol Co and atomic number 27. As with nickel, cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, p ...

and

selenium Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...

in the compound is closest to 1:1; too low a pH will make the compound rich in selenium, while higher The pH will be rich in cobalt.

Applications

Ag⁺-doped cobalt(II) selenide nanoparticles can be used as catalysts for water electrolysis. Cobalt(II) selenide materials mixed with

tin selenide Tin selenide, also known as stannous selenide, is an inorganic compound with the formula Sn Se. Tin(II) selenide is a typical layered metal chalcogenide as it includes a group 16 anion (Se2−) and an electropositive element (Sn2+), and is arrang ...

can be used as electrodes in

dye-sensitized solar cells A dye-sensitized solar cell (DSSC, DSC, DYSC or Grätzel cell) is a low-cost solar cell belonging to the group of thin film solar cells. It is based on a semiconductor formed between a photo-sensitized anode and an electrolyte, a '' photoelectr ...

Related compounds

Cobalt(II) selenide can exist in the form of

non-stoichiometric compound In chemistry, non-stoichiometric compounds are chemical compounds, almost always solid inorganic compounds, having elemental composition whose proportions cannot be represented by a ratio of small natural numbers (i.e. an empirical formula); m ...

s. Dissolve

cobalt(II) chloride Cobalt(II) chloride is an inorganic compound of cobalt and chlorine, with the formula . The compound forms several hydrates ·''n'', for ''n'' = 1, 2, 6, and 9. Claims of the formation of tri- and tetrahydrates have not been confirmed.M. T. Saug ...

and urea in deionized water in a stoichiometric ratio of 1:1, heat to 120 °C in a stainless steel reactor to obtain pink precipitate Co(CO₃)_0.35Cl_0.20(OH)_1.10, wash and vacuum dry. In addition, add selenium powder to the

sodium borohydride Sodium borohydride, also known as sodium tetrahydridoborate and sodium tetrahydroborate, is an inorganic compound with the formula Na BH4. This white solid, usually encountered as an aqueous basic solution, is a reducing agent that finds applica ...

aqueous solution and shake until the black solid disappears to obtain a NaHSe solution. Add the cobalt source and selenium source into the reaction kettle to perform solvothermal (

ethanol Ethanol (abbr. EtOH; also called ethyl alcohol, grain alcohol, drinking alcohol, or simply alcohol) is an organic compound. It is an alcohol with the chemical formula . Its formula can be also written as or (an ethyl group linked to a ...

water Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...

) reaction to obtain Co_0.85Se. This compound is ferromagnetic at room temperature. In addition, Co₉Se₈, Co₂Se₃, Co₃Se₄ and CoSe₂ have also been reported.

References

{{Selenides Cobalt(II) compounds Selenides Nickel arsenide structure type