A facile hydrothermal synthesis of 3D flowerlike CeO2via a cerium oxalate precursor

In this paper, a simple one-step hydrothermal method has been developed to prepare three-dimensional CeO2 microflower structures via a cerium oxalate precursor. X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), field-emission scanning electron microscopy (FE-SEM) and thermal gravimetric (TG) analysis were utilized to characterize the products. Herein, unlike the conventional calcination of a cerium oxalate precursor, oxalic acid acted not only as a precipitator but also as a modifier of morphology with a defined amount of C2O42−, while hydrogen peroxide (H2O2) was introduced as an oxidant to make the full conversion from Ce2(C2O4)3·10H2O to CeO2 in the hydrothermal process with the preserved flowerlike morphology. The as-obtained CeO2 microflowers displayed a high surface area of 147.6 m2 g−1 and narrow pore size of 3.759 nm by N2 adsorption and desorption measurement, and the H2-TPR test showed its better reduction behavior. Furthermore, CeO2 microflowers with hierarchical structures presented a higher catalytic activity for CO oxidation.