posted on 2022-02-17, 17:03authored byChen Li, Xiyan Li, Xiaowang Liu
Dual-mode
luminescent nanomaterials have outstanding performance
in biosensing and multistage anticounterfeiting. Herein, we report
the tuning of optical attributes of lanthanide-doped nanoparticles
(NPs) via simultaneous binary cation exchange. We show that cation
exchange of NaYF4:Yb/Er (18/2 mol %)@NaLnF4 (Ln
= Y and Gd) NPs with a combination of Ce3+ and Tb3+ enables the resultant nanoparticles to exhibit both upconversion
and downshifting emissions upon excitation at 980 and 254 nm, respectively.
We find that in addition to introducing downshifting emission attributes,
the use of Tb3+ ions allows conservation of the integrity
of the parent core@shell NPs by decreasing the dissociation tendency
caused by Ce3+ ions during the cation exchange. The upconversion
color output can be tuned from green to red and blue by changing lanthanide
combinations in the core NPs. This work not only provides an effective
strategy for the optical tuning of lanthanide-doped NPs but also builds
a platform for probing the difference in the reactivity nature of
lanthanides.