Here we report on hydrogen photochromism in V2O5 highly disordered layers, i.e., photochromism that occurs due to hydrogen atoms; the hydrogen being detached under the action of light from organic molecules adsorbed on the oxide surface, whereas the V2O5 layers have been prepared by the sol-gel technology. The comprehensive characterization of the layers has been carried out, as well as the investigation of the parameters influencing their photochromic sensitivity. The high photochromic sensitivity of the V2O5 layers is provided by the surface Grotthuss diffusion of the injected protons. (C) 2014 Elsevier B.V. All rights reserved.