Zn2TiO4 a spinel-type structure photocatalyst, was synthesized by a solid-state reaction method, and obtained as a single phase in the temperature range of 900-1200 oC. The average particle size for case of the as-synthesized Zn2TiO4 sample, sintered at 1200 oC was found to be 5 μm, whereas it lay in the range of 0.5-2 μm for the case of TiO2 calcined at 650 oC. The band gap of Zn2TiO4 and TiO2 (rutile) samples determined by UV-Vis diffuse reflectance spectra (DRS) was 3.10 eV (400 nm). The Zn2TiO4 sample calcined at 1200 oC exhibited a higher hydrogen production rate than that of rutile TiO2 from a watermethanol mixture under UV (λ ≥ 210 nm) and near-visible (μ ≥ 400 nm) light irradiation. In spite of having the same bandgap energy, the photocatalytic activity of Zn2TiO4 was found to be higher than that of rutile TiO2, manily because of its more negative conduction band edge than rutile TiO2.
Keywords: Zn2TiO4, Rutile TiO2, Photocatalysis, Hydrogen production, Visible light