Ambient pressure photoelectron spectroscopy: A new tool for surface science and nanotechnology

The technique of high pressure photoemission or ambient pressure photoelectron spectroscopy is highlighted (APPES). APPES was recently used to investigate the surface composition of aqueous salt solutions, with the aim of determining the possible segregation of ions to the surface, an important problem in atmospheric sciences, where it has been predicted that reactions of sea-salt aerosols with gas phase oxidants such as OH and ozone provide a mechanism for the production of substantial amounts of gas-phase halogen compounds in the troposphere. It has its usefulness in the catalysis area for analysis of surface species, reactants and products during the reaction conditions, and throwing experimental light on the transition from surface-dominated reactions to sub-surface induced chemistry. It is expected that other areas of material and nanoscience will benefit from these developments with the advent of more instruments at various synchrotrons.