Infrared Photon Stimulated Hydrogen Transport in Rutile TiO$_{2}$

Measurements of the O-H and O-D vibrational lifetimes show that the room temperature proton diffusion rate in TiO$_{2}$ can be enhanced by 9 orders of magnitude when stimulated by resonant infrared photons. We find that the local oscillatory motion of the proton quickly couples to a wag-mode-assisted classical transfer process along the c-channel with a jump rate of $>$1 THz and a barrier height of 0.3 eV. Such an increase in proton transport rate at moderate temperatures is significant for renewable energy applications ranging from hydrogen transport membranes to water splitting by photocatalysis.