Effect of lanthanum doping on structural, optical, and photocatalytic properties of YVO4

Abstract

Abstract Yttrium vanadate (YVO4) based undoped and La3+-doped powders were prepared through a solid-state reaction method. The structural characterization carried out with XRD indicating that the samples are crystalline tetragonal type crystal structure of YVO4. XRD of the YVO4: La3+ powder contain same YVO4 diffraction lines and no other lanthanum related impurity and/or secondary phases were detected. Both undoped and La3+-doped YVO4 samples show combined white light emission peaks appeared at 478, 571 and 613 nm. The higher intensity of peaks located at 478 and 571 nm in YVO4: La3+ sample can be attributed to O2−-La3+ and O2−-V5+ charge transfer mechanisms. Besides, photocatalytic activities of the undoped and La3+ doped YVO4 samples were investigated under the UV light irradiation monitoring the aqueous solution of methylene blue (MB) dye. Hence, the effects of La3+ dopant ion on the photoluminescence properties are discussed in detail. While the degradation of MB reaches to 38.8% after 180 minutes of UV light exposure with undoped YVO4, the degradation efficiency of La3+ doped YVO4 reaches 76.7%. Pseudo-first-order reaction rate constant (k) of La3+-doped YVO4 (0.00846 min− 1) is determined 66% greater than undoped one (0.00287 min− 1).