Enhanced photocatalytic hydrogen evolution over nanometer sized Sn and Eu doped titanium oxide

A series of Sn and Eu doped TiO2 (Ti1−(x+0.001)Eu0.001SnxO2−δ where 0.05 ≤ × ≤0.3) nanoparticles have been synthesized by polyol method. Pure TiO2 and Ti0.949Eu0.001Sn0.05O2−δ existed as anatase phases whereas the compositions with higher Sn concentrations contained mixed anatase and rutile phases. The particle size of these nanocrystalline samples was ∼10 to 15 nm. All compositions showed an onset of absorption at ∼450 nm. Photocatalytic activity for hydrogen generation from water–methanol mixture was tested for these samples using sunlight type radiation. Among these catalysts, Ti0.949Eu0.001Sn0.05O2−δ exhibited significantly high activity for hydrogen generation with a quantum efficiency of ∼40% with Pd as co-catalyst. The enhanced activity is attributed to the visible light absorption arising due to the defects associated with the oxygen vacancies and due to the increased reductive power of the composite system.