Ceria Foam with Atomically Thin Single‐Crystal Walls

All in a lather: A three-dimensional CeO2 foam with long-range ultrathin (4–8 Å) single-crystalline walls was synthesized successfully by thermal decomposing CeGeO4 crystals under an NH3 atmosphere. First-principles calculations were also performed to understand the feasibility and reaction pathways of thermal decomposition of CeGeO4. Scale bar: 200 nm.