Selective synthesis of tetragonal LaVO4 with different vanadium sources and its luminescence performance

Pure tetragonal phase LaVO4 (t-LaVO4) was prepared through a simple solution method with different vanadium sources (V2O5, NH4VO3, NaVO3) in the absence of any templates or catalysts. The products were characterized by XRD, TEM, FT-IR and Raman spectroscopies. Effects of pH value, crystallization time, crystallization temperature and vanadium source on the structure and shape of LaVO4 were investigated. The results show that pure t-LaVO4 can be obtained in wide ranges of pH value and crystallization temperature with different vanadium sources as starting material. And vanadium source will affect morphology of the obtained products. Nanoparticles with a diameter of about 30 nm have been obtained. Nanorods with different sizes and aspect ratio have been produced. A process to produce t-LaVO4 was proposed and the process is thought to be feasible for any vanadium sources. A formation mechanism of t-LaVO4 was discussed. A dissoluble complex of La, V, O is presumed as a key factor for producing t-LaVO4 in this mechanism. Luminescence performances of the samples produced with different vanadium sources were also investigated.

► Pure tetragonal (t-) LaVO4 have been obtained with different vanadium sources.
► Different vanadium sources will bring different shapes of the obtained products.
► A common process of obtaining t-LaVO4 with any vanadium sources is proposed.
► A mechanism of selective synthesis of t-LaVO4 is put forward.
► Vanadium source will influence luminescent behavior of the obtained t-LaVO4:Eu.