《Spontaneous Iodide Activation at the Air−Water Interface of Aqueous Droplets》
Website：https://doi.org/10.1021/acs.est.3c05777
Graphical Abstract:
ABSTRACT：
We present experimental evidence that atomic and molecular iodine, I and I2, are produced spontaneously in the dark at the air−water interface of iodide-containing droplets without any added catalysts, oxidants, or irradiation. Specifically, we observe I3- formation within droplets, and I2 emission into the gas phase from NaI-containing droplets over a range of droplet sizes. The formation of both products is enhanced in the presence of electron scavengers, either in the gas phase or in solution, and it clearly follows a Langmuir−Hinshelwood mechanism, suggesting an interfacial process. These observations are consistent with iodide oxidation at the interface, possibly initiated by the strong intrinsic electric field present there, followed by well-known solution-phase reactions of the iodine atom. This interfacial chemistry could be important in many contexts, including atmospheric aerosols.
