Abstract The physical and chemical adsorption of water at the (1 × 1) and (2 × 1)-reconstructed C(111) surfaces are investigated by means of first principles calculations and compared to hydrogen adsorption. The study aims at filling a gap of knowledge about the interaction of water with the most stable diamond surface. The calculated reaction energies and barriers indicate that the Pandey-reconstructed surface is almost inert towards water and hydrogen chemisorption in comparison with the unreconstructed surface and other low-index diamond surfaces. We also show that by increasing the amount of chemisorbed hydroxyl or hydrogen groups the stability of the Pandey reconstruction is progressively reduced with respect to the unreconstructed (111) surface, which becomes energetically more favourable above about 40% of adsorbate coverage. Our results provide a microscopic description of diamond surface passivation, which is very important for controlling macroscale phenomena, such as the friction reduction of diamond coatings in humid environments.

中文翻译：

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金刚石 (111) 表面上的水吸附：从头开始研究

摘要 通过第一性原理计算研究了水在 (1 × 1) 和 (2 × 1) 重构 C(111) 表面的物理和化学吸附，并与氢吸附进行了比较。该研究旨在填补有关水与最稳定的钻石表面相互作用的知识空白。计算出的反应能和势垒表明，与未重建表面和其他低指数金刚石表面相比，Pandey 重建表面对水和氢的化学吸附几乎是惰性的。我们还表明，通过增加化学吸附的羟基或氢基团的量，相对于未重建的 (111) 表面，Pandey 重建的稳定性逐渐降低，这在超过约 40% 的吸附质覆盖率时在能量上变得更加有利。