V-doped ZnO particles: synthesis, structural, optical and photocatalytic properties

In this work, V-doped ZnO particles are synthesis via a simple, reproducible, controllable and direct wet chemical synthesis method. The structure, morphology, optical and luminescent properties of the Zn_1−xV_xO samples have been investigated by X-ray diffraction (XRD), Raman and UV–Vis spectroscopy, transmission electron microscopy (TEM) and photoluminescence. The XRD studies reveal the formation of a hexagonal wurtzite-type structure. The presence of Zn₄V₂O₉ cubic structure can be observed up to 3 mol% V, suggesting that the solubility of the vanadium into the ZnO lattice is limited. The formation of Zn₄V₂O₉ secondary phase at higher V concentration is sustained by Raman spectroscopy, as well. The TEM investigations of the samples illustrate the presence of aggregates with different shapes and dimensions formed by quasi-spherical particles with sizes ranging from 100 to 150 nm. Photocatalytic degradation of Rhodamine B in aqueous solution under UV irradiation in the presence of pure ZnO and V-doped ZnO particles was investigated. The effect of vanadium concentration on the structural and morphological characteristics and on the optical–luminescent and photocatalytic properties was studied. The paper highlights a double correlation between structural characteristics—optical and luminescent properties—and photocatalytic activities for the as obtained V-doped ZnO samples.