作者：Bin Xu，Qitao Zhang，Saisai Yuan，Ming Zhang Teruhisa Ohno
关键字：CeO2 nanoparticles, Hierarchical structure, Porous, Oxygen vacancy, Morphology control
论文来源：期刊
具体来源：Chemical Engineering Journal
发表时间：2015年
In this study, CeO₂ with a broom-like porous hierarchical structure was successfully prepared by a simple template-free hydrothermal method. In the whole hydrothermal process, reaction time and temperature play important roles in morphology control. The morphology of the as-prepared samples was characterized by field emission scanning electron microscopy, transmission electron microscopy and high-resolution transmission electron microscopy. Structure information was obtained by using an X-ray diffractometer and Raman analysis. Analyses of elements and chemical valence analysis were carried on X-ray photoelectron spectroscopy. Absorption edge and band gap energy were investigated by UV–vis diffuse reflectance. In addition, the optimum experimental conditions for target products were determined. Compared with various morphology samples’ BET data, relative intensity of Raman peaks, catalytic evaluation, we can draw a conclusion that CeO₂ with a broom-like porous hierarchical structure has a higher concentration of oxygen vacancies that results in enhancement of catalytic activity. An Ostwald ripening process with orientative self-assembly was proposed for formation of the broom-like porous hierarchical structure.