Ye Sheng

Ionic liquids assisted synthesis and luminescence properties of Ca5(PO4)3Cl:Ce3+,Tb3+ nanostructures

Ca5(PO4)3Cl straw-like sheaves and microrods were synthesized via a ionic liquids based hydrothermal method. The ionic liquids [Omim]Cl was utilized to introduce a new chloride source. The influences of the ionic liquids amount and reaction time on the final products were investigated in detail. A possible splitting formation mechanism for the interesting architectures has been proposed to interpret the growth process. The optical properties of the Ca5(PO4)3Cl:Ce3+,Tb3+ phosphor with different morphology have been discussed. This ionic liquids based hydrothermal method is a novel and facile route for the synthesis of other apatite phosphors.

Preparation, characterization and photoluminescence properties of TiO2:Eu3+ nanorods and nanobelts

TiO2:Eu3+ nanorods and nanobelts were successfully prepared through a simple hydrothermal method followed by a subsequent calcination process. On the basis of X-Ray diffraction, Fourier transform infrared spectroscopy, and transmission electron microscopy results, it can be assumed that the precursors have the structural formula of titanate (H2Ti2O5·H2O). The morphologies of the precursors are nanobelts and nanotubes. However, the nanobelts could transform to anatase TiO2 with the same morphology, while the nanotubes modulate from nanotubes to nanorods after an annealing process. Both the TiO2:Eu3+ nanorods and nanobelts exhibit strong red emission corresponding to the 5D0–7F2 transition of the Eu3+ ions under UV light excitation. However, TiO2:Eu3+ nanobelts showed higher emission intensity than that of the nanorods; the reason is that the nanobelts have less defects.

Growth, structure and optical properties of tartaric acid-templated silica nanotubes by sol–gel method

Photoluminescent nano material has been reported as an intriguing field during the past few decades. In this article, tartaric-templated silica nanotubes were conveniently synthesized by sol–gel method. X-ray diffraction analysis, scanning electron microscopy, transmission electron microscopy, fourier transform infrared spectra and photoluminescence spectra analysis were employed to characterize the growth, structure, morphology and optical property of the products. It is found that tartaric templates can form spindle/spherical-like aggregates composed of many sheets under static/stirring condition, which lead to the different shapes of silica nanotubes. Then the probable strategies for silica nanotubes templating with tartaric acid were described particularly. Hydrogen-bond interaction, supramolecular interaction and a competition of various effects may be the reasons of the nanotubes formation. Moreover, under ultraviolet light excitation, the silica nanotubes exhibited blue emission and luminescent intensity of the tubes prepared under the static condition is much stronger than the stirring ones, mostly because of more defect centers in the structures obtained under stirring condition.