Department of Chemistry, Princeton University, Frick Laboratory, Princeton, NJ 08544, USA.
Phys Chem Chem Phys. 2010 Oct 28;12(40):12956-60. doi: 10.1039/c0cp00116c. Epub 2010 Aug 27.
Density Functional Theory (DFT) calculations within the Generalized Gradient Approximation (GGA) and the GGA + U approach are carried out to investigate the adsorption of O(2) on anatase (101) surfaces having subsurface oxygen vacancies. Our results show that O(2) adsorption is strongly enhanced at sites close to the subsurface defect, whereas dissociation is unfavorable at all sites. The adsorption is accompanied by the transfer of the defect electrons to O(2)-derived electronic states in the anatase surface band gap. Peroxide species (O(2)(2-), O-O = 1.48 Å) are stable when the number of adsorbed O(2) molecules is less or equal the number of defects, whereas superoxide species (O(2)(-), O-O = 1.33 Å) become more favorable at coverages exceeding approximately 1.5 O(2) molecules per oxygen vacancy.
采用广义梯度近似（GGA）和 GGA + U 方法的密度泛函理论（DFT）计算研究了具有亚表面氧空位的锐钛矿（101）表面上 O(2)的吸附。我们的结果表明，O(2)在靠近亚表面缺陷的位置吸附强烈增强，而在所有位置解离都不利。吸附伴随着缺陷电子向锐钛矿表面带隙中 O(2)衍生的电子态的转移。当吸附的 O(2)分子数小于或等于缺陷数时，过氧化物物种（O(2)(2-)，O-O = 1.48 Å）是稳定的，而当覆盖度超过大约 1.5 个 O(2)分子每个氧空位时，超氧化物物种（O(2)(-)，O-O = 1.33 Å）变得更有利。
