Structural-Dependent Photoactivities of TiO2 Nanoribbon for Visible-Light-Induced H2 Evolution: The Roles of Nanocavities and Alternate Structures

Bicrystalline dehydrated nanoribbon (DNR) with alternate structure of TiO(2)(B) and anatase has been prepared by a short-time annealing method. It is photoactive for photocatalytic H(2) evolution from water in the visible region sensitized by a novel heteropoly blue sensitizer. The effects of annealing temperature and time on the DNR phase transformation process have been investigated. These results reveal that the nanocavity structure of TiO(2)(B) exhibits a narrow band gap and improves its absorbance coefficient in the visible region. The alternate structures of TiO(2)(B) and anatase improve interfacial electron separation and transfer. Compared with normal phase junction, the smoothing alternate joints in the band structure of DNR-600-30 provide an effective route for the movement of holes and electrons. This unique alternate bicrystalline structure has a significant advantage on its applications in photocatalysis and nanodevices.