Crystal quality and optical property of MnWO4 nanoparticles synthesized by microwave-assisted method

MnWO4 nanoparticles were prepared using a microwave-assisted method followed by low-temperature treatment. The crystal quality and optical property of the MnWO4 nanoparticles were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and ultraviolet–visible (UV–vis) absorption spectroscopy. Our results show that good crystal quality MnWO4 nanoparticles can be prepared by the microwave-assisted method, and best crystal quality nanoparticles can be obtained with synthesizing pH value of 7. Furthermore, by calcination treatments, crystal quality can be further improved with less defect states and the particle size increases when the calcining temperature increases from 150 to 600 °C. In addition, our study shows that the MnWO4 nanoparticles have strong absorption in the visible light region, suggesting that these nanoparticles are promising for photocatalytic applications.

► MnWO4 nanoparticles have been synthesized by a microwave-assisted method.
► Best crystal quality nanoparticles can be obtained with synthesizing pH value of 7.
► Crystal quality and particle size can be modified by calcination treatment.
► MnWO4 nanoparticles have strong absorption in the visible light region.
► MnWO4 nanoparticles would be promising for photocatalytic applications.