Preparation and up-conversion fluorescence of rare earth (Er3+ or Yb3+/Er3+)-doped TiO2 nanobelts

Anatase TiO2 nanobelts doped with rare earth (RE) ions Yb3+, Er3+ or Yb3+/Er3+ have been prepared using layered titanate nanobelts (LTO NBs) with RE ions as the precursor obtained by ion-exchange between LTO NBs and RE ions under hydrothermal process. Various measurement results demonstrate that the RE ions have doped into the lattice of TiO2, and the Er3+ or Yb3+/Er3+ doped nanobelts show strong visible up-conversion (UC) fluorescence under 980 nm excitation. The UC emission intensity of LTO NBs embedded with Er3+ or Yb3+/Er3+ is slightly higher than that of the corresponding TiO2 nanobelts doped with RE ions, whereas higher RE doping content leads to the decrease of UC emission intensity due to the concentration-quenching effect. - Graphical abstract: Anatase TiO2 nanobelts doped with Er3+ or Yb3+/Er3+ cations were simply synthesized using two-step preparation proceedings of ion-exchange and hydrothermal treatment, and their upconversion emissions were also investigated. SEM images of TiO2 nanobelts (NBs) doped with Er3+ (the left) and codoped with Yb3+/Er3+ (the right).