Spectroscopic studies of hydrogen adsorbed on zinc oxide (kadox 25)

Abstract

The vibrational spectra (320–2230 cm^–1) of ZnO and of hydrogen adsorbed on ZnO have been obtained by incoherent inelastic neutron-scattering spectroscopy (INS). The v_s and v_δ modes of type I Zn—H surface species are observed at 829 and 1708 cm^–1, in accord with published i.r. data. The recent assignments by Boccuzzi et al. of the v_δ mode of type I O—H species and the v_as mode of type II [graphic omitted] species to weak i.r. bands at ca. 850 and 1475 cm^–1, respectively, are not corroborated by the INS results.

No resolved bands assignable to type II species are observed. The INS spectrum of ZnO contained a previously unreported, intense feature at 1346 cm^–1 which was unchanged on hydrogen adsorption. This feature is assigned to impurities within the bulk. Raman and i.r. data of ZnO are also discussed.