Liu Yani, Feng Haifeng, Yan Xiaobing, Wang Jiaou, Yang Huagui, Du Yi, Hao Weichang
Department of Physics and Key Laboratory of Micro-Nano Measurement, Manipulation and Physics, Ministry of Education, Beihang University, Beijing 100191, China.
Dalton Trans. 2017 Aug 15;46(32):10694-10699. doi: 10.1039/c7dt00827a.
The photocatalytic activity of semiconductors is largely governed by their light absorption, separation of photoinduced charge carriers and surface catalytically active sites, which are primarily controlled by the morphology, crystalline size, structure, and especially the electronic structure of photocatalysts. Black TiO is recognized as one of the most promising visible-light photocatalysts, due to its significantly enhanced visible-light photocatalytic performance in comparison to intrinsic TiO. In this work, black TiO is synthesized through the hydrogenation process. The sample shows a TiO@TiO core/shell structure which is attributed to hydrogenation. By using X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS), and nuclear magnetic resonance (NMR) spectroscopy, we identified the featured midgap electronic states in black TiO, which gave rise to the TiO shell layer. These states lead to the improvement of visible-light absorption and the separation of photoinduced charge carriers, which consequently result in remarkable enhanced photocatalytic activities in black TiO.
半导体的光催化活性很大程度上取决于其光吸收、光生电荷载流子的分离以及表面催化活性位点，而这些主要由光催化剂的形态、晶体尺寸、结构，尤其是电子结构控制。黑色TiO被认为是最有前途的可见光光催化剂之一，因为与本征TiO相比，其可见光光催化性能显著增强。在这项工作中，通过氢化过程合成了黑色TiO。该样品呈现出TiO@TiO核壳结构，这归因于氢化作用。通过使用X射线光电子能谱（XPS）、X射线吸收光谱（XAS）和核磁共振（NMR）光谱，我们确定了黑色TiO中具有特征的带隙中间电子态，正是这些态形成了TiO壳层。这些态导致可见光吸收的改善和光生电荷载流子的分离，从而使黑色TiO的光催化活性显著增强。
