Bismuth subcarbonate (BiO)
2CO
3, sometimes written Bi
2O
2(CO
3) is a chemical compound of
bismuth containing both
oxide
An oxide () is a chemical compound that contains at least one oxygen atom and one other element in its chemical formula. "Oxide" itself is the dianion of oxygen, an O2– (molecular) ion. with oxygen in the oxidation state of −2. Most of the E ...
and
carbonate
A carbonate is a salt of carbonic acid (H2CO3), 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 g ...
anions. Bismuth is in the +3
oxidation state
In chemistry, the oxidation state, or oxidation number, is the hypothetical charge of an atom if all of its bonds to different atoms were fully ionic. It describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. C ...
. Bismuth subcarbonate occurs naturally as the mineral
bismutite. Its structure consists of Bi–O layers and CO
3 layers and is related to
kettnerite, CaBi(CO
3)OF. It is light-sensitive.
Uses
It is highly
radiopaque and for example is used as a
filler in radiopaque
catheters which can be seen by x-ray. In modern medicine, bismuth subcarbonate has been made into
nanotube
A nanotube is a nanometer-scale hollow tube-like structure.
Kinds of nanotubes
* BCN nanotube, composed of comparable amounts of boron, carbon, and nitrogen atoms
* Boron nitride nanotube, a polymorph of boron nitride
* Carbon nanotube, includes g ...
arrays that exhibit antibacterial properties. It is also used in fireworks to make
Dragon's egg
''Dragon's Egg'' is a 1980 hard science fiction novel by American writer Robert L. Forward. In the story, Dragon's Egg is a neutron star with a surface gravity 67 billion times that of Earth, and inhabited by cheela, intelligent creatures ...
s. It is a constituent of milk of bismuth which was a popular digestive tract
panacea
In Greek mythology, Panacea (Greek ''Πανάκεια'', Panakeia), a goddess of universal remedy, was the daughter of Asclepius and Epione. Panacea and her four sisters each performed a facet of Apollo's art:
* Panacea (the goddess of universal ...
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 (CO
2) 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-Bi
2O
3 and γ-Bi
2O
3) nanoparticles even when they are not suspended in water.
Structure
Bismuth subcarbonate has a structure with a tetragonal unit cell. Layers of (BiO)
''n'' positively charged, and carbonate anion (CO
32-) are surrounding both sides of the (BiO) layer to compensate the charge. Usually, The (BiO)
'n'' layer grows perpendicular to the b axis.
[
]
References
External links
Source of the common name; milk of bismuth
{{Carbonates
Bismuth compounds
Carbonates