Gd-N共掺杂SrTiO_3/TiO_2复合纳米纤维制备及光催化性能

Preparation and Photocatalytic Activity of Gd-N Co-doped SrTiO_3/TiO_2 Composite Nanofibers

以静电纺丝技术制备的TiO_2纳米纤维为基质和反应物,结合一步水热法制得Gd-N共掺杂SrTiO_3/TiO_2复合纳米纤维光催化剂。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、高分辨透射电镜(HRTEM)、X射线光电子能谱(XPS)、紫外-可见漫反射(UV-Vis DRS)和荧光光谱(PL)等方法对其微观结构、形貌和光学性能进行表征。结果表明:SrTiO_3和TiO_2形成异质结能够使光生电子和空穴得到很好的分离,而Gd-N共掺杂产生新带隙,可以拓宽光谱响应范围至可见光区,并引起晶格缺陷,成为光生电子-空穴对的浅势捕获阱。Gd-N共掺杂与异质结的协同作用有效提高了SrTiO_3/TiO_2复合纳米纤维的可见光催化活性。

Gd and N co-doped SrTiO3/TiO2 composite nanofibers were prepared via one step hydrothermal synthesis growth of SrTiO3 nanostructures using electrospun anatase TiO2 nanofibers as both substance and reactant. The phase composition, microstructure, morphology and optical properties of the sample were characterized by X-ray diffraction (XRD), scanning electron mictoscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (XPS), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) and photoluminescence spectroscopy (PL). The results indicated that the heterostructure formed by SrTiO3 and TiO2, plays an important role in the suppression of electron-hole recombination and improves the photocatalytic performance of TiO2 nanofibers. The excellent visible light photocatalytic activity of this substance may be due to the generation of a new band gap that enables the catalyst to absorb visible light and results in the lattice defects which acts as a recombination center of photoinduced electrons and holes. The synergistic effect of Gd-N co-doping and heterojunction could effectively improve the visible-light photocatalytic activity of SrTiO3/TiO2 composite nanofibers.