Photodesorption of NO from Ag(111) and Cu(111)

Publisher Website
Google Scholar
Abstract
The adsorption, thermal reactions, and photoreactions of NO on Ag(111) and Cu(111) at 80–85 K have been studied by thermal‐desorption spectroscopy (TDS), high‐resolution electron‐energy‐loss spectroscopy (HREELS), and photon‐induced desorption. Adsorption of NO on both surfaces is quite complicated. At saturation coverage, a number of chemical species are present, including atop and bridge‐bonded NO, atomic N and O, and N2O. Photodesorption of NO, N2, and N2O is observed simultaneously under low‐power photon irradiation in the wavelength range for 260–600 nm. From TD and HREEL spectra before and after photon irradiation, it is established that on both surfaces the atop NO is photoactive. Photon polarization, power‐, and wavelength‐dependences studies indicate that the mechanisms for photodesorption are nonthermal. A substrate‐mediated mechanism involving photogenerated carriers at low photon energies (<3 eV) and a direct excitation mechanism of the adsorbate‐surface complex at high photon energies are used to explain the observed photodesorption.