Kristoffersen Henrik H, Shea Joan-Emma, Metiu Horia
Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106-9510, United States.
J Phys Chem Lett. 2015 Jun 18;6(12):2277-81. doi: 10.1021/acs.jpclett.5b00958. Epub 2015 Jun 4.
Coadsorbed water is often unavoidable in electrochemistry and low-temperature catalysis. In addition, water influences the adsorption of biomolecules on surfaces. We use ab initio DFT molecular dynamics and ground-state calculations to study the adsorption of HCl and catechol on the rutile TiO2(110) surface and at a water-rutile interface. We find that a coadsorbed water film reduces the adsorption energy of both catechol and HCl significantly because water molecules must be displaced from the surface before catechol or HCl can adsorb. The adsorption energy of catechol (or HCl) at the water-rutile interface can be estimated as the adsorption energy in vacuum minus the energy to remove two water molecules (respectively, one water molecule) from the rutile surface in vacuum and place them in liquid water. This estimate predicts the effect of a surface water film on adsorption without the need of molecular dynamics.
在电化学和低温催化中，共吸附水往往不可避免。此外，水会影响生物分子在表面的吸附。我们使用从头算密度泛函理论（DFT）分子动力学和基态计算方法，研究了HCl和邻苯二酚在金红石型TiO2(110)表面以及水 - 金红石界面的吸附情况。我们发现，共吸附的水膜会显著降低邻苯二酚和HCl的吸附能，这是因为在邻苯二酚或HCl吸附之前，水分子必须从表面被取代。邻苯二酚（或HCl）在水 - 金红石界面的吸附能可以估计为真空中的吸附能减去从真空中的金红石表面移除两个水分子（分别为一个水分子）并将它们置于液态水中所需的能量。这种估计无需分子动力学就能预测表面水膜对吸附的影响。
