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

Abstract In this paper, we report the obtention of MnWO 4 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 MnWO 4 nanocrystals. This green method is an effective approach to the controlled growth of MnWO 4 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 MnWO 4 microcrystals with different shapes was discussed in detail.