• hydrogel;
  • lanthanide;
  • nanotubes;
  • photoluminescence;
  • self-assembly


Functional photoluminescent materials are emerging as a fascinating subject with versatile applicability. In this work, luminescent organic–inorganic hybrid hydrogels are facilely designed through supramolecular self-assembly of sodium cholate, and lanthanide ions such as Eu3+, Tb3+, and Eu3+/Tb3+. Fluorescence microscopy and TEM visualization demonstrates the existence of spontaneously self-assembled nanofibers and 3D networks in hybrid hydrogel. Photoluminescence enhancement of lanthanide ions is realized through coordination with cholate and co-assembly into 1D nanofibers, which can successfully shield the Eu3+ from being quenched by water. The photoluminescence emission intensity of a hybrid hydrogel exhibits strong dependence on europium/cholate molar ratio, with maximum emission appearing at a stoichiometry of 1:3. Furthermore, the emission color of a lanthanide–cholate hydrogel can be tuned by utilizing different lanthanide ions or co-doping ions. Moreover, photoluminescent lanthanide oxysulfide inorganic nanotubes are synthesized by means of a self-templating approach based on lanthanide–cholate supramolecular hydrogels. To the best of our knowledge, this is the first time that the lanthanide oxysulfide inorganic nanotubes are prepared in solution under mild conditions.