Synthesis and photocatalytic properties of TiO2 and Pt pillared HCa2Nb3O10 doped with various rare earth ions

TiO2 and Pt pillars were constructed in the interlayer of H1−xCa2−xLnxNb3O10 (Ln=La, Nd, Eu, x=0–0.75) by the stepwise intercalation reactions. The amounts of TiO2 and Pt incorporated were 0.5–2.9 and 0.04–0.19 wt.%, respectively. The height of TiO2 and Pt pillar was less than 0.5 nm. TiO2 and/or Pt pillared compounds were capable of water cleavage into hydrogen and oxygen by the band gap irradiation without a sacrificial hole scavenger although no water cleavage proceeded by using H1−xCa2−xLnxNb3O10 separately. The photocatalytic activity for water cleavage was in the order H1−xCa2−xLnxNb3O10/Pt>H1−xCa2−xLnxNb3O10/(Pt, TiO2)>H1−xCa2−xLnxNb3O10/TiO2 and that of Pt pillared nanocomposite was in the order H1−xCa2−xLaxNb3O10/Pt>H1−xCa2−xEuxNb3O10/Pt>H1−xCa2−xNdxNb3O10/Pt.