CeO₂ Nanostructures Prepared by Selective Water‐Soluble Sr₃Al₂O₆(SAO)‐CeO₂ Vertically Aligned Nanocomposite

The unique redox properties and high oxygen capacity of nanostructured CeO₂ demonstrate a wide range of applications, such as electrolytes for solid oxide fuel cells, gas sensors, and catalysis for automotive exhaust gas. Most CeO₂ nanomaterials are prepared by chemical synthesis or hard templating methods. An effective way to obtain highly textured, small‐radius dimensions with high specific surface area remains challenging. Here, highly textured CeO₂ nanostructures with various shapes ranging from nanowires to nanoporous thin films are successfully synthesized. Vertically aligned nanocomposites (VANs) of Sr₃Al₂O₆ (SAO) and CeO₂ are synthesized first while varying concentration ratio between them. Once the SAO is dissolved in water, the remaining CeO₂ forms distinct nanostructures. The thermal stability of the nanostructured CeO₂ is evaluated by in situ heating XRD and thermal annealing tests. This method provides an alternative approach to preparing nanostructured CeO₂ without toxic chemical solutions or complex micro/nanofabrication techniques. These results present a novel approach to prepare nanostructured CeO₂ for future sensing and energy device applications.