Application of Mn3O4 nanowires in the dye waste water treatment at room temperature

Abstract

Size controllable Mn3O4 nanowires are prepared by facile hydrothermal method with KMnO4 used as source material. The prepared Mn3O4 nanowires exhibits high activity in the treatment of dyes such as Gentian violet, Methylene blue, Rhodamine B and Methyl orange in acid condition. Effect of pH on the performance of nanowires are investigated. The 10 mg Mn3O4 nanowires can efficiently deal with 50 mL Methylene blue solution (20 mg·L−1) at pH 2 and 25 °C in 30 min. The material shows high recycling during dye treatment. After 5th cycles of treatment of Methylene blue, the Mn3O4 nanowires still can dispose of more than 95% dye in 30 min. The nanowires before and after treatment are characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).