Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang, 110016, China.
Laboratory for Advanced Materials & Electron Microscopy, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
Adv Mater. 2018 Feb;30(6). doi: 10.1002/adma.201704479. Epub 2018 Jan 8.
Increasing visible light absorption of classic wide-bandgap photocatalysts like TiO has long been pursued in order to promote solar energy conversion. Modulating the composition and/or stoichiometry of these photocatalysts is essential to narrow their bandgap for a strong visible-light absorption band. However, the bands obtained so far normally suffer from a low absorbance and/or narrow range. Herein, in contrast to the common tail-like absorption band in hydrogen-free oxygen-deficient TiO , an unusual strong absorption band spanning the full spectrum of visible light is achieved in anatase TiO by intentionally introducing atomic hydrogen-mediated oxygen vacancies. Combining experimental characterizations with theoretical calculations reveals the excitation of a new subvalence band associated with atomic hydrogen filled oxygen vacancies as the origin of such band, which subsequently leads to active photo-electrochemical water oxidation under visible light. These findings could provide a powerful way of tailoring wide-bandgap semiconductors to fully capture solar light.
为了促进太阳能转化，人们长期以来一直致力于提高 TiO 等经典宽带隙光催化剂的可见光吸收率。调节这些光催化剂的组成和/或化学计量比对于缩小其带隙以获得强可见光吸收带至关重要。然而，迄今为止获得的带隙通常存在吸收率低和/或范围窄的问题。相比之下，在无氢缺氧气相 TiO 中，常见的尾部吸收带，在锐钛矿 TiO 中通过有意引入原子氢介导的氧空位，可以实现跨越整个可见光光谱的不寻常的强吸收带。实验表征与理论计算相结合，揭示了与填充氧空位的原子氢相关的新亚价带的激发是产生这种带的原因，进而导致在可见光下进行有效的光电化学水氧化。这些发现为定制宽带隙半导体以充分捕获太阳光提供了一种有力的方法。
