Nanotubular titanic acid obtained by hydrothermal method was selected as a precursor to prepare platinum decorated TiO 2−x N x via a facile one-pot route. Photocatalytic activity of Pt/TiO 2−x N x for visible-light induced degradation of propylene was evaluated in relation to the synergistic effect among single-electron-trapped oxygen vacancies and dopants N plus Pt. It is proposed that oxygen vacancies induce a new sub-band between the valence band and conduction band of TiO 2 resulting in visible light response of Pt/TiO 2−x N x ; the synergistic effect among oxygen vacancies and dopants leads to enhanced photocatalytic activity of as-synthesized Pt/TiO 2−x N x . Moreover, the effect of chemical state of dopants on visible light photoactivity is discussed in detail.