Low temperature synthesis of hollow La2Mo2O9 spheres by the molten salt solvent method

Abstract

In this paper, nearly mono-disperse La₂Mo₂O₉ hollow microspheres were explored through the molten solvent salt route for the first time. Employing LiNO₃, KNO₃ and KCl as the solvents, and La(NO₃)₃·nH₂O, (NH₄)₆Mo₇O₂₄·4H₂O as the reactants, hollow structured La₂Mo₂O₉ microspheres were successfully fabricated at temperatures lower than 120 °C while no other additives or templates were introduced into the reaction system. The effects of various reaction conditions on the morphology and size of the products were investigated. Both KCl and LiNO₃ were found to play important roles in the construction of the hollow sphere microstructure and KCl content is concluded to be responsible for the hollowing evolvement of the La₂Mo₂O₉ particles. Based on the experimental results, a mechanism of crystal growth of La₂Mo₂O₉ is suggested.