This study investigated the effect of TiO2 morphology-driven intrinsic oxygen defects on photocatalytic activities for removal of Cr(VI). To do so, two different-shaped TiO2 particles, nano-granular TiO2 particles (TiNP) and TiO2 nanotube particles (TiNT), were prepared and applied. The surface analyses indicated that TiNP was found to have a greater photocatalytic activity than TiNT because of its more crystallinity and lower bandgap energy, more oxygen vacancies closer to the conduction band (CB), and its resulting more amounts of photogenerated electrons. Accordingly, these photocatalytic properties of TiO2 particles were more evident in experimental result for photocatalytic reduction of Cr(VI) that was tested as a model target compound. The batch system showed that TiNP completely reduced Cr(VI) to Cr(III) at acidic and neutral pH, whereas TiNT were less effective even at low pH. (C) 2017 Elsevier B.V. All rights reserved.