Cooke David J, Marmier Arnaud, Parker Stephen C
Department of Chemistry, University of Bath, BATH, United Kingdom.
J Phys Chem B. 2006 Apr 20;110(15):7985-91. doi: 10.1021/jp0564445.
We have calculated the stability of two of the low-index surfaces known to dominate the morphology of ZnO as a function of stoichiometry. These two surfaces are (10(-)10) and (11(-)20). In each case, two terminations only are stable for a significant range of oxygen and hydrogen chemical potential: the pure stoichiometric surface and a surface covered in a monolayer of water. The mode by which the water adsorbs is however different for the two surfaces considered. On the (10(-)10) surface the close proximity of the water molecules means hydrogen bonding can occur between adjacent chemiabsorbed water molecules and hence there is little difference in the stability of the hydrated and hydroxylated surface, and in fact the most stable surface occurs with a combination of dissociated and undissociated water adsorption. In the case of the (11(-)20) surface, it is only when full dissociation has occurred that a hydrogen-bonding network can form. Our results also show good agreement between DFT and atomistic simulations, suggesting that potential based methods can usefully be applied to ZnO.
我们已经计算了已知主导氧化锌形态的两个低指数表面的稳定性，其作为化学计量比的函数。这两个表面是(10(-)10)和(11(-)20)。在每种情况下，对于显著范围的氧和氢化学势，只有两种终止态是稳定的：纯化学计量表面和覆盖有单层水的表面。然而，对于所考虑的两个表面，水吸附的模式是不同的。在(10(-)10)表面上，水分子的紧密接近意味着相邻化学吸附水分子之间可以发生氢键作用，因此水合表面和羟基化表面的稳定性几乎没有差异，实际上最稳定的表面是解离和未解离水吸附的组合。在(11(-)20)表面的情况下，只有当完全解离发生时才能形成氢键网络。我们的结果还表明密度泛函理论(DFT)和原子模拟之间有很好的一致性，这表明基于势的方法可以有效地应用于氧化锌。
