Radiation-Induced Chemical Changes to Iron Oxides.

The radiolysis of a variety of iron oxide powders with different amounts of associated water has been performed using γ rays and 5 MeV (4)He ions. Adsorbed water was characterized by both temperature-programmed desorption and diffuse reflection infrared Fourier transform spectroscopy to reveal a variety of active sites on the surface. Molecular hydrogen production was found only from water adsorbed on Fe2O3, and the yield was several orders of magnitude greater than that of bulk water.