Anisotropic growth of gas-liquid precipitated ceria mesocrystals to wires several micrometers in length.

Ceria (CeO 2 ) wires with lengths of 6 μm and diameters of tens of nanometers are fabricated through the anisotropic growth of mesocrystals. In the gas-liquid precipitation process, an aqueous Ce(NO 3 ) 3 solution is used as a starting material and NH 3 gas is used to induce CeO 2 precipitation at the gas-liquid interface. CeO 2 mesocrystals, formed by this process at 60 °C, grow in the direction of 〈011〉 into micrometer length wires exposing {001} and {011} on their side walls. It is shown that the initial pH of the starting material solution is a key parameter to attain anisotropic growth of the CeO 2 mesocrystals. We thus propose the formation mechanism of micrometer length-CeO 2 wires from mesocrystals.