National Laboratory of Solid State Microstructures, Department of Physics, Ecomaterials and Renewable Energy Research Center (ERERC), and College of Engineering and Applied Sciences, Nanjing University, 22 Hankou Road, Nanjing 210093, People's Republic of China.
Phys Chem Chem Phys. 2013 Oct 14;15(38):16054-64. doi: 10.1039/c3cp51613j. Epub 2013 Aug 22.
Water adsorption and dissociation on the perfect, oxygen containing and nitrogen vacancy containing Ta3N5(100) surfaces are systematically studied by density functional theory calculations. The results show that the perfect Ta3N5(100) surface is very active for water dissociation because of the dangling bonds formed on the perfect Ta3N5(100) surface. The presence of oxygen on the surface is able to stabilize the Ta3N5(100) surface but not to facilitate water dissociation, which may be ascribed to the saturation of surface dangling bonds by oxygen. The presence of a nitrogen vacancy on the surface is able to facilitate water dissociation, but Ta3N5(100) surfaces with nitrogen vacancies are not stable. We found that keeping the impurity oxygen as less as possible is one effective approach to enhance the water splitting ability of Ta3N5. We propose that doping with foreign elements is one potential method to obtain a clean Ta3N5(100) surface, since the oxygen concentration may be adjusted by competition between oxygen and foreign elements.
通过密度泛函理论计算，系统地研究了完美的、含氧的和含氮空位的 Ta3N5(100)表面上水的吸附和解离。结果表明，由于完美 Ta3N5(100)表面上形成的悬空键，完美 Ta3N5(100)表面对水的解离非常活跃。表面上存在氧可以稳定 Ta3N5(100)表面，但不利于水的解离，这可能归因于氧对表面悬空键的饱和。表面存在氮空位可以促进水的解离，但含氮空位的 Ta3N5(100)表面不稳定。我们发现，尽可能少地保持杂质氧是提高 Ta3N5 水分解能力的有效途径。我们提出，通过掺杂外来元素是获得清洁 Ta3N5(100)表面的一种潜在方法，因为氧浓度可以通过氧和外来元素之间的竞争来调节。
