Bismuth subcarbonate (BiO)₂CO₃, sometimes written Bi₂O₂(CO₃) is a chemical compound of

bismuth Bismuth is a chemical element; it has symbol Bi and atomic number 83. It is a post-transition metal and one of the pnictogens, with chemical properties resembling its lighter group 15 siblings arsenic and antimony. Elemental bismuth occurs nat ...

containing both

oxide An oxide () is a chemical compound containing at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion (anion bearing a net charge of −2) of oxygen, an O2− ion with oxygen in the oxidation st ...

and

carbonate A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...

anions. Bismuth is in the +3

oxidation state In chemistry, the oxidation state, or oxidation number, is the hypothetical Electrical charge, charge of an atom if all of its Chemical bond, bonds to other atoms are fully Ionic bond, ionic. It describes the degree of oxidation (loss of electrons ...

. Bismuth subcarbonate occurs naturally as the mineral

bismutite Bismutite or bismuthite is a bismuth carbonate mineral with formula Bi2(CO3)O2 ( bismuth subcarbonate). Bismutite occurs as an oxidation product of other bismuth minerals such as bismuthinite and native bismuth in hydrothermal veins and pegma ...

. Its structure consists of Bi–O layers and CO₃ layers and is related to kettnerite, CaBi(CO₃)OF. It is light-sensitive.

Uses

It is highly

radiopaque Radiodensity (or radiopacity) is opacity to the radio wave and X-ray portion of the electromagnetic spectrum: that is, the relative inability of those kinds of electromagnetic radiation to pass through a particular material. Radiolucency or hypode ...

and for example is used as a filler in radiopaque

catheter In medicine, a catheter ( ) is a thin tubing (material), tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgical procedure. ...

s which can be seen by x-ray. In modern medicine, bismuth subcarbonate has been made into

nanotube A nanotube is a nanoscale cylindrical structure with a hollow core, typically composed of carbon atoms, though other materials can also form nanotubes. Carbon nanotubes (CNTs) are the most well-known and widely studied type, consisting of rolled- ...

arrays that exhibit antibacterial properties. It is also used in fireworks to make Dragon's eggs. It is a constituent of milk of bismuth which was a popular digestive tract

panacea In Greek mythology and religion, Panacea (Greek ''Πανάκεια'', Panakeia), a goddess of universal remedy, was the daughter of Asclepius and Epione. Mythology Panacea and her four sisters each performed a facet of Apollo's art: * Panac ...

in the 1930s.

Safety

Bismuth subcarbonate may be harmful if swallowed. It may irritate the respiratory and gastrointestinal tract.

Synthesis

Bismuth subcarbonate can be attained from the reaction between bismuth nanoparticles and the atmospheric carbon dioxide (CO₂) dissolved in water. Bismuth subcarbonate has the tendency to form nanoplates, but it can be also obtained as small round nanospheres (with controlled size) when it is grown in the presence of halloysite nanotubes. The high pH and high temperature of the aqueous solution helps to reduce the time of synthesis. It is readily formed on the surface of undoped bismuth oxide (β-Bi₂O₃ and γ-Bi₂O₃) nanoparticles even when they are not suspended in water.

Structure

Bismuth subcarbonate has a structure with a tetragonal unit cell. Layers of (BiO) positively charged, and carbonate anion (CO) are surrounding both sides of the (BiO) layer to compensate the charge. Usually, the (BiO) layer grows perpendicular to the axis.

References

External links

Source of the common name; milk of bismuth
{{Carbonates Bismuth compounds Carbonates