Vacuum Ultraviolet Photoelectron Emission Spectroscopy of Water and Aqueous Solutions.
Abstract
Experimental methods are developed for the photoelectron emission spectroscopy of water and aqueous solutions (halides, hydroxyl ion, phosphoric acid and phosphates) up to 10.5 eV. The yield for emission of photoelectrons by the liquid into water vapor is measured as a function of photon energy. Threshold energies are determined by extrapolation from emission spectra. Photoelectron emission by liquid water obeys Urbach's rule and has a threshold energy of 9.3 + or - 0.3 eV. This threshold is compared with the literature value of 8.7 + or - 0.1 eV for the threshold energy for amorphous ice. Threshold energies for halide and hydroxyl ions are obtained by application of the Brodsky-Tsarevsky theory of photoelectron emission by solutions: 8.7, 7.9, 7.2, 8.4 eV, respectively, for Cl-, Br-, I-, OH- ions. The emission spectrum for Br- is deconvoluted for spin-orbit coupling. The threshold energies of these ions are higher by 1.6 to 1.8 eV than the energies at the maxima of the corresponding charge-transfer-to-solvent absorption spectra. The difference of 1.6 to 1.8 eV agrees with a theoretical prediction. Preliminary results are reported on the effect of ionic charge on the emission of phosphoric acid and phosphate ions. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1980
- Accession Number
- ADA081980
Entities
People
- Iwao Watanabe
- James B. Flanagan
- Paul Delahay
Organizations
- New York University