Ultrasonic‐assisted Solution‐Phase Synthesis and Property Studies of Hierarchical Layer‐by‐Layer Mesoporous CeO2

Hierarchical layer‐by‐layer quadrangle CeO2 was prepared through ultrasonic‐assisted solution‐phase synthesis strategy using cerium oxalate as the precursor. The as‐prepared mesoporous CeO2 displayed a surface area of 98.7 m2 g−1 and pore diameters of 2.0–10.0 nm. The high‐resolution TEM image revealed that the layer structures of the CeO2 were made of numerous nanocrystal particles with the crystallite size of about 13–15 nm. High energy and cavitation of ultrasonic wave assists cerium oxalate precursor in building the layer‐by‐layer quadrangle staking. UV–vis absorption spectrum showed that the direct allowed transition bandgap energy for the as‐prepared CeO2 was 2.91 eV. Moreover, the CeO2 exhibited good photocatalytic property for degrading Rhodamine B solution under UV radiation.