光催化
材料科学
化学工程
化学物理
纳米技术
氢
光化学
化学
催化作用
工程类
生物化学
有机化学
作者
Hao Zhang,Jinmeng Cai,Yating Wang,Moqing Wu,Ming Meng,Ye Tian,Xingang Li,Jing Zhang,Lirong Zheng,Zheng Jiang,Jinlong Gong
标识
DOI:10.1016/j.apcatb.2017.08.046
摘要
Abstract This paper describes the effects of defect distribution on energy band structure and the subsequent photocatalytic activity over TiO2 with exposed {001} facets as the model catalyst. Our results show that only surface oxygen vacancies (Vo’s) and Ti3+ centers in TiO2 can be induced by hydrogenation treatment, whereas the generation of bulk Vo’s and Ti3+ species depends on the thermal treatment in nitrogen. Both the surface and bulk defects in TiO2 can promote the separation of electron-hole pairs, enhance the light absorption, and increase the donor density. The presence of surface and bulk defects in TiO2 can not change the valence band maximum, but determine the conduction band minimum. Surface defects in TiO2 induce a tail of conduction band located above the H+/H2 redox potential, which benefits the photocatalytic performance. However, bulk defects in TiO2 generate a band tail below the H+/H2 potential, which inhibits hydrogen production. Thus, the change of band gap structure by defects is the major factor to determine the photocatalytic activity of TiO2 for hydrogen evolution. It is a new insight into the rational design and controllable synthesis of defect-engineered materials for various catalytic processes.
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