Simulated photoelectron intensities at the aqueous solution-air interface for flat and cylindrical (microjet) geometries.

Ion spatial distributions at the aqueous-air/vacuum interface are accessible by energy-dependent X-ray photoelectron spectroscopy (XPS). Here we quantify the difference between a flat surface and a cylindrical microjet in terms of the energy-dependent information depth of the XPS experiment and in terms of the simulated photoelectron intensities using solutions of pure water and of 1 mol L-1 NaI as examples.