TiO₂ nanotube photocatalytic oxidation for water treatment

Heterogeneous photocatalysis is a promising technology in addressing the incapability of current water technology. In this present paper, we proposed the fabrication of one-dimensional TiO₂ nanotubes through hydrothermal method. Various techniques were used to characterize the nanotubes, i.e. FESEM, HRTEM, XRD and BET. Subsequently, the evaluation of photocatalytic oxidative (PCO) properties of TiO₂ nanotubes are compared with the commercial TiO₂ P25 (i.e. TiO₂ powder) in PCO batch reactor. The TiO₂ nanotubes show excellent performance with complete photodegradation of humic acid (HA) in comparison with the 97.7% removal efficiency of P25. The TiO₂ nanotubes are also tested in membrane filtration for verification of catalyst separation and recovery. The TiO₂ nanotubes were totally separated and recovered with membrane filtration. Lastly, its stability is tested in repeated reuse experiments. No catalyst deactivation is observed after five consecutive PCO experiments of newly added HA. Therefore, our novel nanostructured photoctalyst is an advancement in photocatalytic technology that has significant impact for current water technology.