Facile synthesis of NiO@Gd2O3:Er3+,Yb3+ hollow nanocomposites with mesoporous, upconversion luminescence and magnetic properties

Multifunctional NiO@Gd 2 O 3 :Er 3+ ,Yb 3+ hollow nanocomposites (NCs) with mesoporous, upconversion (UC) luminescent and magnetic properties are synthesized by a facile hydrothermal process. Transmission electron microscope (TEM) and scanning electron microscope (SEM) images reveal that the samples have hollow structures with double shells of UC layer and magnetic layer. N 2 adsorption/desorption isotherm analysis shows the samples have large surface area of 29.052 m 2 /g and typical mesoporous structure. Multicolored UC luminescence at 521 nm, 541 nm and 654 nm are obtained under 980 nm laser excitation. In addition, the measured magnetic hysteresis loops indicate the samples exhibit high superparamagnetic behavior (15.8 emu/g). These multifunctional NCs have potential applications in the field of fluorescence probe, targeted therapy, magnetic separation, etc.