Dysprosium(III) carbonate is an inorganic compound with the chemical formula Dy<sub>2</sub>(CO<sub>3</sub>)<sub>3</sub>. It is a white, paramagnetic solid.
An amorphous tetrahydrate exists, stable in air up to near the decomposition temperature. It progressively looses water upon heating and is directly converted to dysprosium oxide (Dy<sub>2</sub>O<sub>3</sub>) by dehydration and carbonate calcination:
An orthorhombic kozoite-type DyCO<sub>3</sub>OH forms under hydrothermal conditions, and a poorly crystalline tengerite-type Dy<sub>2</sub>(CO<sub>3</sub>)÷2-3H<sub>2</sub>O remains stable at ambient temperature.
Dysprosium(III) carbonate can be prepared by reacting a soluble dysprosium salt such as dysprosium(III) chloride with sodium carbonate, forming a white gel-like precipitate. The flow rate of the Dy(III) solution and the reactor temperature affect the particle size of the product.
Another method involves the hydrolysis of dysprosium trichloroacetate in a homogeneous phase reaction:
Carbon dioxide and chloroform are formed as byproducts in this reaction.
It can also be prepared by passing carbon dioxide through a suspension of dysprosium hydroxide or oxide in water. The conversion is slow and may not produce a pure product. The reaction is fast with higher yields if supercritical CO<sub>2</sub> at high pressure is used instead.
It can be used as a photocatalyst for the degradation of methyl orange under ultraviolet light.
The crystal structures of the hydroxide carbonate (DyOHCO<sub>3</sub>) and another basic carbonate (Dy<sub>2</sub>O<sub>2</sub>CO<sub>3</sub>) have been determined. They can be prepared by hydrothermal synthesis involving the reaction of dysprosium(III) chloride and carbon dioxide with caesium carbonate and potassium carbonate respectively.
The dysprosium tetracarbonate complex [C(NH<sub>2</sub>)<sub>3</sub>]<sub>4</sub>[Dy(CO<sub>3</sub>)<sub>4</sub>(H<sub>2</sub>O)](H<sub>3</sub>O)÷13H<sub>2</sub>O has been characterized by single-crystal X-ray diffraction. It can be prepared by treating saturated guanidinium carbonate solution with dysprosium nitrate.