Zn-Assisted TiO2–xPhotocatalyst with Efficient Charge Separation for Enhanced Photocatalytic Activities

A new Zn-assisted method has been employed to synthesize reduced TiO2(TiO2–x) photocatalyst via a one-step hydrothermal process. In order to prevent the oxidation of TiO2–xin air, hydrofluoric acid is introduced in the preparative process for the stabilization of the Ti3+and oxygen vacancies, as confirmed by low-temperature electron paramagnetic resonance. The obtained reduced TiO2presents a wide-spectrum solar light absorption, including the near-infrared region. In addition, {110}–{111} and {101}–(001) dual-facet exposures are generated by Cl- and F-based surface-terminated reagents, respectively. The generated {001} and {101} facets on reduced TiO2samples act as hole and electron collectors, respectively, which contributes to the charge separation of the catalyst. Finally, the synergistic effect between Ti3+doping and dual-facet exposure results in the high photocatalytic performance for degradation of Rhodamine B and formic acid.