Sonochemical preparation of pure t-LaVO4 nanoparticles with the aid of tris(acetylacetonato)lanthanum hydrate as a novel precursor

• Pure tetragonal phase LaVO4 nanoparticles were produced by ultrasound irradiation.
• Tris(acetylacetonato)lanthanum hydrate ([La(acac)3·3H2O]) was used as a novel precursor.
• The XRD results showed that monoclinic phase LaVO4 could be obtained without sonication.

Herein a simple and fast method is introduced for the synthesis of lanthanum orthovanadate (LaVO4) nanoparticles under ultrasound irradiation. The effect of tris(acetylacetonato)lanthanum hydrate ([La(acac)3·3H2O]) and La(OAc)3 as two different precursors on the morphology and phase purity of LaVO4 was investigated. To optimum the particle size of the products, sonication time and the kind of surfactants have been changed. The as-synthesized products were characterized by XRD, FT-IR, SEM, TEM, and EDS. Based on the obtained results, it was found that the size and shape of the sonochemically formed LaVO4 nanoparticles were dramatically dependent on the sonication time, type of surfactant and lanthanum precursor. According to the XRD results, it was observed that pure tetragonal phase lanthanum orthovanadate (t-LaVO4) could be obtained only by using [La(acac)3·3H2O] as precursor under ultrasound irradiation for 30 min. On the other hand, monoclinic phase lanthanum orthovanadate (m-LaVO4) with poor crystallinity has been produced by vigorous stirring at room temperature without sonication.