Preparation by Co-precipitation Method and Photocatalytic Performances on the Degradation of Dyes of Ce3+-Doped Nano-ZnO

A series of nano-ZnO doped with different amounts of cerium were prepared by co-precipitation method with Zn(NO3)(2 center dot)6H(2)O and Ce(NO3)3 center dot 6H(2)O as raw materials. The as-made samples were characterized by powder X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and UV-visible diffuse reflectance spectroscopy (UV-Vis DRS). Some samples were further characterized by X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL). Photocatalytic activity of these materials toward photodegradation of methylene blue (MB) was evaluated under UV and sunlight irradiation, respectively. It was found that the sample with 3% Ce3+ doped ZnO, named as ZnO-3%Ce, exhibited highest photocatalytic activity among the prepared samples and its MB-degradation efficiency was over 98%. Then, the sample of ZnO-3% Ce was selected to further evaluate its photocatalytic activity toward photodegradation of rhodamine B (RhB) and methyl orange (MO) under both UV and sunlight irradiation. The results showed that the sample of ZnO-3%Ce presented good photodegradation activity under both UV and sunlight condition. The order of photodegradation efficiency under sunlight irradiation was as follows: MB>RhB>MO, while the photocatalytic activity under UV irradiation was increased by the following order RhB>MB>MO. The stability of ZnO-3%Ce catalyst was studied by cyclic experiments. The results showed that the photodegradation efficiency still retained more than 97% after three cycles, suggesting that the catalyst maintained its structure and component and presented good stability and application prospect.