Chelating ligand-mediated crystal growth of cerium orthovanadate

An ethylenediaminetetraacetic acid (EDTA)-mediated hydrothermal route to cerium orthovanadate (CeVO4) microcrystals has been developed. The EDTA/Ce3+ ratio, solution pH, and temperature of the reaction systems are found to play important roles in determining the morphologies and growth process of the CeVO4 products. During the process of synthesis, EDTA plays important roles such as chelating ligand and capping reagent. These products have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Moreover, the results of X-ray photoelectron spectra (XPS) and magnetic measurements reveal the existence of Ce4+ induced by surface oxidation of air. The existence of Ce4+ ions may be helpful for oxidative dehydrogenation of propane of CeVO4. On the basis of the experimental results, we suppose this method may have wide applications in exploring the crystal growth process and may provide guidance for the morphology controllable synthesis.