Spectroscopic studies of hydrogen adsorbed on zinc oxide (kadox 25)
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 vs and vδ 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 vδ mode of type I O—H species and the vas 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.