Measurements of the O-H and O-D vibrational lifetimes showed that the room-temperature hydrogen diffusion rate in rutile TiO2 could be enhanced by 9 orders of magnitude when stimulated by resonant infrared light. It was found that the local oscillatory motion of the proton quickly coupled to a wag-mode-assisted classical transfer process along the c channel with a jump rate of greater than 1 THz and a barrier height of 0.2eV. This increase in proton transport rate at moderate temperatures provides new insight into hydrogen transport in solids, which could play a role in applications ranging from fuel cells to hydrogen production.

Giant Enhancement of Hydrogen Transport in Rutile TiO2 at Low Temperatures. Spahr, E.J., Wen, L., Stavola, M., Boatner, L.A., Feldman, L.C., Tolk, N.H., Lüpke, G.: Physical Review Letters, 2010, 104[20], 205901