The interaction of hydrogen and a ZnO(00•¯1)-O surface was investigated using a temperature programmed desorption technique. When the surface was exposed to atomic hydrogen below 400K, hydrogen was adsorbed on the surface. As the hydrogen exposure increases, bulk diffusion of hydrogen takes place. The existence of surface and bulk hydrogen was confirmed using X-ray photo-electron spectroscopy. When the ZnO surface dosed with hydrogen was heated, surface hydrogen was desorbed at 432K and bulk hydrogen was evolved at ∼539K. Diffusion of hydrogen into the ZnO bulk was an activated process, and the activation energy was estimated to be 0.19eV.

Interaction of Hydrogen with ZnO: Surface Adsorption versus Bulk Diffusion. Doh, W.H., Roy, P.C., Kim, C.M.: Langmuir, 2010, 26[21], 16278-81