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使用密度泛函理论(GGA/PBE)对H2O在Fetet1-和Feoct2-终结Fe3O4(111)表面的吸附行为进行了研究。对于Fetet1-终结表面,在1/5 ML覆盖度下,带有氢键的H2O分子以及异裂解离的结构具有最高的稳定性,而类似水合氢离子的OH3+-OH结构出现在2/5 ML覆盖度下,其次为带有氢键的水的聚合体。这些结果与实验中观测到的现象一致。对于Feoct2-终结表面,在1/6 ML覆盖度下,分子态H2O的吸附是有利的,而在1/3 ML覆盖度下多种吸附形式共存。H2O吸附在Fetet1-终结表面比吸附在Feoct2-终结表面热力学上更有利。此外,通过计算局域态密度(LDOS)对吸附机理进行了分析。
Adsorption behavior of H2O on Fetet1- and Feoct2-terminated Fe3O4 (111) surfaces was investigated using density functional theory (GGA / PBE). For the Fetet1-terminated surface, H2O molecules with hydrogen bonds and dissociatively cleaved structures have the highest stability at 1/5 ML coverage, while OH3 + -OH structures similar to hydronium ions appear at 2/5 ML Coverage, followed by the hydrogen bond with the water polymer. These results are consistent with the observations in the experiment. For the Feoct2-terminated surface, molecular H2O adsorption is favorable at 1/6 ML coverage, whereas multiple adsorption forms coexist at 1/3 ML coverage. H2O adsorption on the Fetet1-terminated surface is more thermodynamically more favorable than adsorption on the Feoct2-terminated surface. In addition, the adsorption mechanism was analyzed by calculating the local state density (LDOS).