Radiolysis of Water on ZrO₂ Nanoparticles

The radiolysis of water adsorbed on the surface of ZrO2 nanoparticles has been examined using a variety of spectroscopic techniques. Irradiations were performed with fast electrons, γ rays, and 5 MeV helium ions. Infrared spectroscopic analysis of the surface reveals little change in the surface stoichiometry, which probably indicates the relative insensitivity of this technique to the doses given. X-ray photoelectron spectroscopy reveals a loss in the relative number of terminal OH groups on the surface with radiolysis. The maximum production of excess H2 is found when a single water layer or less is adsorbed on the terminal OH surface layer. Little or no H2 seems to come from the surface-bound OH groups.