Characterization and their photocatalytic properties of Ln_2Zr_2O_7 (Ln = La, Nd, Sm, Dy, Er) nanocrystals by stearic acid method

摘要

Fine-particle rare-earth metal zirconates Ln_2Zr_2O_7 (Ln = La, Nd, Sm, Dy, Er) with cubic structure were prepared by stearic acid method. Zirconium nitrate and rare-earth nitrate were as raw materials, and stearic acid was used as solvent and dispersant. The as-prepared Ln_2Zr_2O_7 nanocrystals were characterized by XRD, FT-IR, TEM and HRTEM. The results showed that the preparation temperature was lowered (from 1500 deg C to 800 deg C) and the reaction time was shortened (from at least 10 h to 5 h) by stearic acid method, compared with transitional solid-state method. The photocatalytic activity of Ln_2Zr_2O_7 nanocrystals was evaluated by the photocatalytic degradation of methyl orange. With the increase of the atomic number, the photocatalytic activity trend of obtained Ln_2Zr_2O_7 (Ln = La, Nd, Sm, Dy, Er) nanocrystals was in agreement with the change trend of magnetic moment of the rare-earth metal ion. The photoactivity of Ln_2Zr_2O_7 was strongly dependent on Ln, decreasing in the sequence of Dy > Nd > Er > Sm > La.