کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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1571458 | 1514418 | 2012 | 7 صفحه PDF | دانلود رایگان |
Pure monoclinic and tetragonal LaVO4:Eu nanocrystals with various morphologies were successfully synthesized by a hydrothermal method in the presence of ethylenediaminetetraacetic acid [EDTA or H4L, where L4− = (CH2COO)2 N (CH2)2 N(CH2COO)24−]. It was found that tuning the pH of the growth solution was a crucial step for the synthesis of LaVO4:Eu nanocrystals with controllable crystal structure and morphology. When the pH value was lower than 2.5, urchin-like monoclinic LaVO4:Eu nanostructures were obtained. Increasing the pH value can induce the phase transformation from monazite to zircon type accompanied with the morphology transformation: urchin-like → bundle → nanorod/nanowire. In addition, the concentration of EDTA also played an important role in determining the aspect ratio of tetragonal LaVO4:Eu nanorods. The possible mechanism responsible for the phase control and morphology evolution of the LaVO4:Eu nanocrystals was discussed. Their luminescent properties were systematically studied. It demonstrated that the phase transformation from monazite to zircon type and the increase in the aspect ratio of LaVO4:Eu nanorods resulted in a remarkable improvement of the luminescent properties.
Graphical AbstractFigure optionsDownload as PowerPoint slideHighlights▶ LaVO4:Eu nanocrystals with various shapes were synthesized by a hydrothermal method. ▶ The aspect ratio of LaVO4:Eu nanocrystals can be controlled. ▶ LaVO4:Eu nanocrystals with high aspect ratio exhibit higher emission intensity.
Journal: Materials Characterization - Volume 69, July 2012, Pages 108–114