Shape-controlled synthesis of MnWO4 nanocrystals by a surfactant-free hydrothermal method

In this paper, we report the obtention of MnWO4 nanocrystals with different shapes, such as: nanospheres, nanorods, and urchin-like microspheres were synthesized by a surfactant-free hydrothermal method. The as-obtained powders were characterized by X-ray diffraction patterns and transmission electron microscopy. XRD patterns indicate that these crystals have a wolframite-type monoclinic structure without deleterious phases. The TEM images revealed that the pH values and precursors played a key role in the morphology-controlled synthesis of MnWO4 nanocrystals. This green method is an effective approach to the controlled growth of MnWO4 nanocrystals with different shapes, which are of interest for both theoretical investigations and practical applications. Finally, a possible growth mechanism for the formation of the MnWO4 microcrystals with different shapes was discussed in detail.