Picaud Sylvain, Collignon Barbara, Hoang Paul N M, Rayez Jean-Claude
Institut UTINAM-UMR CNRS 6213, Université de Franche-Comté, 16 route de Gray, F-25030, Besançon Cedex, France.
Phys Chem Chem Phys. 2008 Dec 14;10(46):6998-7009. doi: 10.1039/b811126j. Epub 2008 Oct 14.
In this paper, molecular dynamic simulations are used to study the adsorption of water molecules on partially oxidized graphite surfaces containing COOH and OH sites. More specially, the competition between the OH and COOH sites with respect to water adsorption is characterized at three different temperatures (200, 250 and 300 K). The simulations show a strong preferential clustering of the water molecules around the COOH sites irrespective of the temperature. The present results also show that the OH sites can influence the water adsorption process at high temperature, if their local density on the surface is sufficiently large. In this situation, the dynamics of the adsorption process is shown to depend on the distribution of these OH sites on the surface. These results give insights into the water adsorption mechanisms on oxidized graphite surfaces constituting, for example, black carbons or soot particles emitted by aircraft.
在本文中，分子动力学模拟用于研究水分子在含有COOH和OH位点的部分氧化石墨表面上的吸附。更具体地说，在三个不同温度（200、250和300 K）下，表征了OH和COOH位点在水吸附方面的竞争。模拟结果表明，无论温度如何，水分子在COOH位点周围都有强烈的优先聚集。目前的结果还表明，如果表面上OH位点的局部密度足够大，OH位点可以在高温下影响水的吸附过程。在这种情况下，吸附过程的动力学取决于这些OH位点在表面上的分布。这些结果为氧化石墨表面上的水吸附机制提供了见解，例如构成飞机排放的黑碳或烟尘颗粒的氧化石墨表面。
