Synthesis, characterization and luminescence study of Eu(III) tungstates and molybdates nanotubes using carbon nanotubes as templates

Eu(III) tungstates and molybdates nanotubes have been successfully synthesized by the solvothermal method using carbon nanotubes (CNTs) as removable templates. The products were characterized by X-ray diffraction spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric and differential thermalanalysis. It is demonstrated that CNTs are fully coated with an amorphous Eu2(MO4)3 (M = W, Mo) layer, which is about 10 nm thick and almost continuous and uniform. After the Eu2(MO4)3 (M = W, Mo)/CNTs composites have been calcined at 700 °C, Eu2(MO4)3 (M = W, Mo) nanotubes are obtained by removing the CNTs templates. The diameter of the Eu2(MO4)3 (M = W, Mo) nanotubes is 40–60 nm, which is consistent with that of CNTs. The luminescence properties of the Eu2(MO4)3 (M = W, Mo) nanotubes calcined at various temperatures have been investigated. The result shows that the Eu2(MO4)3 (M = W, Mo) nanotubes obtained from the Eu2(MO4)3 (M = W, Mo)/CNTs composites calcined at 700 °C display a strong red emission peak at around 611 nm.