Controlling the synergistic effect of oxygen vacancies and N dopants to enhance photocatalytic activity of N-doped TiO<sub>2sub> by H<sub>2sub> reduction
- 作者：Zizhong Zhang<sup> ; sup><sup>z.zhang@fzu.edu.cnsup><sup> ; sup><sup>zizhong_zhang@hotmail.comsup> ; Jinlin Long ; Xiuqiang Xie ; Huaqiang Zhuang ; Yangen Zhou ; Huan Lin ; Rusheng Yuan ; Wenxin Dai ; Zhengxin Ding ; Xuxu Wang<sup> ; sup><sup>xwang@fzu.edu.cnsup> ; Xianzhi Fu
- 关键词：N-doped TiO2 ; H2 reduction ; Oxygen vacancies ; Synergistic effect ; Ethylene photooxidation
- 刊名：Applied Catalysis A ; General
- 出版年：2012
- 期刊代码：4_0926860x
- 类别：ch
- 出版时间：28 May, 2012
- 卷：425-426
- 期：Complete
- 页码：117-124
- 文件大小：1928 K
摘要
This paper focuses on improving photocatalytic activity of N-doped TiO<sub>2sub> photocatalyst for efficiently utilizing solar energy. A simple H<sub>2sub> reduction is found to remarkably enhance the photocatalytic activity of N-doped TiO<sub>2sub> for ethylene oxidation under visible light or simulated solar light irradiation. Ultraviolet/visible diffuse reflectance spectra (UV/vis DRS), X-ray photoelectron spectra (XPS) and electron paramagnetic resonance (EPR) spectra were employed to characterize the surface properties and chemical states of nitrogen dopants in H<sub>2sub>-reduced N-doped TiO<sub>2sub>. The results reveal that H<sub>2sub> reduction facilitates the creation of oxygen vacancies and Ti<sup>3+sup> species in N-doped TiO<sub>2sub> but without removal of nitrogen species from catalyst surface. The formed oxygen vacancies and Ti<sup>3+sup> species seriously influence electron excitation from doped nitrogen species and subsequently tune the generation of active oxygen species O<sub>2sub><sup>鈭?/sup> radicals on N-doped TiO<sub>2sub>. The synergistic effect of oxygen vacancies and doped nitrogen species contributes to the enhancement of photocatalytic activity of N-doped TiO<sub>2sub> samples, but the formed Ti<sup>3+sup> ions largely suppress the photocatalytic activity.