Polymorphism and Optical–Vibration Properties of MnV₂O₆·<i>n</i>H₂O (<i>n</i> = 0, 2, 4) Prepared by Microwave Irradiation

Polymorphism and optical–vibration properties of manganese vanadates were investigated as a function of the microwave irradiation conditions. Single-phase, impurity-free materials were prepared and described as monoclinic MnV2O6·H2O (C2/c, No. 15), orthorhombic MnV2O6·2H2O (Pnma, No. 62), and monoclinic MnV2O6 (C2/m, No. 12). The structural, morphological, and optical–vibration properties of the hydrated and anhydrous phases were investigated by X-ray diffraction, transmission electron microscopy, and Raman spectroscopy. Vibrational studies for these materials are reported for the first time. The chosen synthesis methodology was shown to be a less time- and energy-consuming process compared to previous studies. The results of this work complement the knowledge about manganese vanadates and improve the possibilities of future applications for these materials as catalysts in several processes