Solvothermal synthesis of La-based metal-organic frameworks and their color-tunable photoluminescence properties

Abstract

A series of La-based metal−organic frameworks (La-MOFs) phosphors have been successfully synthesized by a facile solvothermal method without assistance of any surfactant or template. The results show that the ethanol volume ratio is important to obtain adjustable shape and size of La-MOFs in the synthesis process. The obtained samples possess flake-like architectures with about 3–5 μm in length. Under UV excitation, all the La-MOFs:Tb3+, Eu3+ phosphors exhibit the characteristic emissions of Tb3+ and Eu3+. Moreover, the emitting color of the as-obtained products can be acquired from green, green-yellow, yellow, yellow-orange, orange, to red owing to the efficient energy transfer (ET) between Tb3+ and Eu3+ions. The ET efficiency of the samples was calculated, and the maximum was found about 96.84%. Furthermore, the dipole–quadrupole interaction has been reasonable proved by the energy transfer between Tb3+ and Eu3+. These results indicated that La-MOFs:Tb3+, Eu3+ might be as a novel potential candidate as phosphors for displays and lightings.