静电纺丝法制备氧化铈纳米纤维及光催化性能

Synthesis and Photocatalytic Properties of Cerium Oxide Nanofibers by Electrospinning

采用静电纺丝法合成了CeO_(2)纳米纤维,利用X-射线衍射光谱(XRD)、扫描电镜(SEM)、透射电镜(TEM)、红外光谱(FT-IR)、X-射线光电子能谱(XPS)和紫外-可见漫反射(UV-Vis DRS)对氧化铈纳米纤维进行表征。通过光催化还原Cr(Ⅵ)评估CeO_(2)纳米纤维的光催化活性。结果表明,制备的CeO_(2)纳米纤维纯度较高、分散均匀,具有较大的长径比;纳米材料中Ce元素主要以+4和+3价态存在,部分Ce^(3+)的存在促进了氧缺陷的形成;CeO_(2)纳米纤维的形成有效调节了CeO_(2)的禁带宽度,增强了其可见光吸收性能;在酸性条件下,可在60 min内实现Cr(Ⅵ)的完全还原,其反应速率常数是P25的8.2倍,同时CeO_(2)纳米纤维具有良好的稳定性,电子是该还原反应的主要活性物种。

CeO_(2)nanofibers were synthesized by electrospinning,and characterized by X-ray diffraction spectroscopy(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),and ultraviolet visible diffuse reflectance(UV-Vis DRS).The photocatalytic activity of CeO_(2)nanofibers was evaluated by photocatalytic reduction of Cr(Ⅵ).The results suggested that the prepared CeO_(2)nanofibers had high purity,uniform dispersion,and a large aspect ratio.In nanomaterials,Ce mainly exists in the+4 and+3 valence states,and the presence of some Ce^(3+)promotes the formation of oxygen defects.The formation of CeO_(2)nanofibers effectively adjusts the band gap width of CeO_(2)and enhances its visible light absorption performance.Under acidic conditions,the complete reduction of Cr(Ⅵ)could be achieved within 60 min,with a reaction rate constant of 8.2 times that of P25.Meanwhile,CeO_(2)nanofibers had good stability,and electrons were the main active species in this reduction reaction.