Impacts of morphology and crystallite phases of titanium oxide on the catalytic ozonation of phenol.

TiO(2) nanomaterial is widely used for catalytic ozonation. In the present work, TiO(2) nanostructures with various morphology and crystallite phases were synthesized by a hydrothermal method, followed by calcination using Degussa P25 as precursor. The nanotube, nanorod, and nanowire forms were obtained by varying the hydrothermal temperature, and the anatase/rutile ratios were adjusted by controlling the annealing temperature. The catalytic activity of the samples was evaluated by degradation of phenol in aqueous solution in the presence of ozone. We found that the initial degradation rates (IDR) of phenol were dominated primarily by the surface OH groups. Thus, with the help of transmission electron microscopy (TEM), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) analyses, the number of surface OH groups per unit area of TiO(2) was correlated with the morphology and crystallite phases. Finally, we conclude that the vast surface area and higher rutile phase ratios are favorable for the catalytic ozonation of phenol and the morphology of TiO(2) had negligible effect in our experiments.