The effects of PVP surfactant in the direct and indirect hydrothermal synthesis processes of ceria nanostructures

Abstract CeO 2 nanostructures with completely different morphologies were successfully prepared using the same cerium source and mineralizer through the direct and indirect hydrothermal methods with different introducing strategies of PVP surfactant. The CeO 2 nanostructures tend to form the morphologies of nano-flowers and nano-cubes through the indirect and direct hydrothermal methods, respectively. X-ray diffraction (XRD) analyses revealed that both as-prepared nanostructures are composed of CeO 2 with a standard fluorite structure. The different synthesis mechanisms and corresponding chemical evolutions of the as-prepared CeO 2 nanostructures are discussed based on the different introducing strategies of PVP surfactant in the direct and indirect hydrothermal processes. Investigation of the UV-shielding ability of both CeO 2 nanostructures suggested that the UV absorbance of the nano-flowers is much higher than that of the nano-cubes.