棒状LaVO_4∶Dy^(3+)纳米晶的水热合成及荧光性能研究

Hydrothermal synthesis and fluorescence of LaVO_4∶Dy^(3+) nanorod

以La_2O_3、Dy_2O_3、浓HNO_3、偏钒酸钠、氢氧化钠、无水乙醇、乙二醇为原料,采用十六烷基三甲基溴化铵(CTAB)辅助水热法合成了四方晶系锆石结构的LaVO_4∶Dy^(3+)棒状纳米晶体。并用X粉末衍射(XRD)、扫描电镜(SEM)、红外光谱(FT-IR)和荧光光谱(FL)对产品进行了表征和分析。测试结果表明,所得样品为四方锆石型结构,反应pH从7升至10,纳米棒增长60～70nm。LaVO_4∶Dy^(3+)纳米棒分别在574nm和484nm处有较强的黄光发射(~4F_(9/2)→~6H_(13/2))和蓝光跃迁(~4F_(9/2)→~6H_(15/2)),通过改变反应的pH和Dy^(3+)掺杂量达到对黄蓝光强度比值(Y/B)的有效调控,Y/B值最大达1.207。

La2O3,Dy2O3,HNO3,NaVO3,NaOH,C2H5OH and CH2OHCH2OH were used as raw materials,LaVO4∶Dy^3+nanorods were successfully prepared via a facile hydrothermal method assisted by cetyltrimethyl ammonium bromide(CTAB).The as-prepared preducts were characterized by X-ray diffraction,scanning electron microscope,infrared spectrum and fluorescence spectra.The results showed that,all the samples were well crystallized and assigned to the zircon-type tetragonal(t-)phased LaVO4 nanorods.The nanorods were changed with different reaction pH value.With the increase of pH value from 7 to 10,the grain of sample became longer about 60~70 nm.LaVO4∶Dy^3+ nanorods exhibited simultaneously the blue(484 nm)and yellow(574 nm)emissions.The broad blueyellow emissions were attributed to 4F9/2→6H15/2 and 4F9/2→6H13/2 transition of Dy^3+ ion in LaVO4 matrix.In addition,the LaVO4∶Dy3+nanorods exhibited the strongest yellow emisson and blue emission,and the Y/B value can be controlling via different reaction pH and Dy-doped concentration.Furthermore,it can obtain the largest Y/B value(1.207).