Xu Meiling, Wang Sheng, Wang Hui
State Key Lab of Superhard Materials and College of Physics, Jilin University, Changchun 130012, People's Republic of China.
Phys Chem Chem Phys. 2017 Jun 28;19(25):16615-16620. doi: 10.1039/c7cp03457a.
An anatase TiO(001) surface has shown great potential as an ideal and powerful photocatalyst due to its chemical stability, nontoxicity, and high reactivity. However, the fundamental atomic structure of the reconstructed anatase (001)-(1 × 4) surface is still under debate, which greatly impedes further exploration of its chemical activity. Herein, the anatase (001)-(1 × 4) surface reconstruction and the photocatalytic reactivity have been extensively studied using an effective surface structure searching method in combination with the first-principles calculations. Our study reveals that there exist two stable (1 × 4) reconstructed surfaces, i.e., the previously proposed "ad-molecule" (ADM) and oxidized ridge (OR) surface structures, and their simulated STM images are in good agreement with experimental observations. Moreover, we find that the ADM surface has superior photocatalytic reactivity to the OR surface and a small number of water can be dissociated at the terrace at one water monolayer coverage, which has never been found before. These findings can not only be applied to solve the experimental controversies about the atomic structure of the reconstructed anatase (001)-(1 × 4) surface but also provide a theoretical basis for exploring the intrinsic properties of the surface.
锐钛矿型TiO(001)表面因其化学稳定性、无毒和高反应活性，已展现出作为一种理想且强大的光催化剂的巨大潜力。然而，重构的锐钛矿(001)-(1×4)表面的基本原子结构仍存在争议，这极大地阻碍了对其化学活性的进一步探索。在此，利用一种有效的表面结构搜索方法结合第一性原理计算，对锐钛矿(001)-(1×4)表面重构和光催化反应活性进行了广泛研究。我们的研究表明，存在两种稳定的(1×4)重构表面，即先前提出的“吸附分子”(ADM)和氧化脊(OR)表面结构，并且它们的模拟扫描隧道显微镜(STM)图像与实验观测结果高度吻合。此外，我们发现ADM表面比OR表面具有更优异的光催化反应活性，并且在单层水覆盖下，台地处能解离少量水，这是此前从未发现的。这些发现不仅可用于解决关于重构的锐钛矿(001)-(1×4)表面原子结构的实验争议，还可为探索该表面的本征性质提供理论基础。
