Characterization of Oxygen Vacancy Associates within Hydrogenated TiO2: A Positron Annihilation Study
Characterization of Oxygen Vacancy Associates within Hydrogenated TiO2: A Positron Annihilation Study
复制标题
氢化 TiO2 中氧空位缔合物的表征：正电子湮灭研究
DOI：
10.1021/jp307573c
复制
发表时间：
2012-10-25
影响因子：
3.7
通讯作者：
Pan, Chunxu
中科院分区：
文献类型：
--
作者：
Jiang, Xudong;Zhang, Yupeng;Pan, Chunxu
介绍了一种利用正电子湮没寿命谱（帕尔斯）表征氢化改性TiO 2中氧空位缔合物的新方法。结果表明，在氢化TiO 2中引入了大量的小的中性Ti 3 +-氧空位缔合物，一些较大尺寸的空位团，以及少量空位缔合物空隙。这些缺陷使原子晶格高分辨透射电子显微镜（HRTEM）图像变得模糊，并导致新的拉曼振动出现。X射线光电子能谱（XPS）测量表明，在TiO 2晶格中的氧空位的浓度为3%。光致发光（PL）光谱、光电流和亚甲基蓝降解实验表明，加氢引入的氧空位缔合物抑制了电荷复合，从而显著提高了光催化活性。
This paper introduces a novel method for characterizing the oxygen vacancy associates in hydrogenation-modified TiO2 by using a positron annihilation lifetime spectroscopy (PALS). It was found that a huge number of small neutral Ti3+-oxygen vacancy associates, some larger size vacancy clusters, and a few voids of vacancy associates were introduced into hydrogenated TiO2. The defects blurred the atomic lattice high-resolution transmission electron microscopy (HRTEM) images and brought about the emergence of new Raman vibration. X-ray photoelectron spectroscopy (XPS) measurement indicated that the concentration of oxygen vacancies was 3% in the TiO2 lattice. The photoluminescence (PL) spectroscopy, photocurrent, and degradation of methylene blue indicated that the oxygen vacancy associates introduced by hydrogenation retarded the charge recombination and therefore improved the photocatalytic activity remarkably.