Lanthanide–titanium-oxalate clusters and their degradation products, photocurrent response and photocatalytic behaviours

Incorporation of lanthanide ions (Ln) into TiO2 nanomaterials has recently been proved to be an efficient strategy to explore photoelectric active materials. Herein, three lanthanide-titanium oxo-clusters (LnTOCs), formulated as [Ln(2)Ti(6)O(2)(C2O4)(4)(NO3)(2)((OPr)-Pr-i)(20)]2HO(i)Pr (Ln = La (1), Ce (2) and Eu (3)), are reported. Their structures feature two Ti3O13 subunits and a central La2O14 subunit bridged by four oxalate ions. The cluster core is surrounded by 20 (OPr)-Pr-i groups, which easily undergo dealkoxy reactions. TOCs have now been used as photocatalytic materials under ambient conditions, and in most cases they should already not be the original clusters due to their sensitivity to moisture. However, less work on the degradation clusters has been discussed. In this work, the degradation products were carefully characterized and polymeric Ln-TiO-C2O4 materials were obtained. Using such materials, photocurrent response and photocatalytic dye degradation were examined. The improvements in the photocurrent intensity and photocatalytic activity of dye-degradation are attributed to the cooperative effects of lanthanide and oxalate doping in TiO catalysis.