Geminal recombination reduces photolysis efficiency in condensed matter. However, it has been shown previously that photolysis of the same compounds can be more efficient in heterogeneous environments (thin films and aerosols), than in bulk solution, for example in the case of aqueous sodium nitrate. Photolysis of nitrate is an anthropogenic source of ozone. Recently published photolysis experiments have demonstrated that the photolysis efficiency of nitrate differs with respect to the type of cation present in solution (Richards-Henderson et al., PCCP, 2015, 17:32211). Using molecular dynamics simulations with polarizable force fields, we show a strong correlation between the photolysis of nitrate and the surface propensity of nitrate in our simulations. Different cations have stabilizing and destabilizing effects on nitrate ion partitioning at and near the air-water interface. We contrast this with the predicted behavior of a spherical anion, chloride, whose photolysis yields chlorine radical, which can result in either the formation or destruction ozone, depending on the other chemicals present.

Counter-ions influence nitrate photolysis yields through altering interfacial concentrations

253rd National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.