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Indexed by:期刊论文

Date of Publication:2017-07-27

Journal:JOURNAL OF PHYSICAL CHEMISTRY C

Included Journals:SCIE、EI、Scopus

Volume:121

Issue:29

Page Number:15746-15755

ISSN No.:1932-7447

Abstract:The adsorption of nitrobenzene at the surface of hexagonal ice was studied by grand canonical Monte Carlo (GCMC) simulations at 200 K by employing TIP5P water model and our modified force field for nitrobenzene. We found that the number of adsorbed nitrobenzene molecules gradually increases with relative pressure before the condensation point and the condensation precedes the monolayer adsorption saturation. The adsorption follows the Langmuir shape only up to a very low coverage. At this low coverage, the adsorption of the molecules occurs independently from each other to adsorption sites (called alpha sites), where adsorbed nitrobenzene molecules lie almost in parallel with the ice surface to facilitate strong electrostatic interactions with ice surface. More importantly, in the alpha-type adsorption, a typical O-H center dot center dot center dot p bond for the adsorption of aromatics on the ice surface is not preferable for nitrobenzene. With increasing surface coverage, additional adsorbed molecules do not take unoccupied a sites due to attractive interactions among adsorbates, inducing a deviation of the adsorption isotherm from the Langmuir shape. In addition, the calculated adsorption energy (-75.98 kJ/mol) for nitrobenzene agrees well with the value (-71.35 kJ/mol) from our validating quantum chemistry calculations, implying the reliability of the results from GCMC simulations.