Plant-assisted synthesis and characterization of MnO 2 nanoparticles for removal of crystal violet dye: an environmental remedial approach.

The current study is focused on the use of the Caryota mitis Lour. (Fishtail palm) flower extract as a reducing agent for the preparation of manganese dioxide (MnO 2 ) nanoparticles. Scanning electron microscopy (SEM), four-phase infrared analysis (FT-IR), and x-ray diffraction (XRD) methods were used to characterize the MnO 2 nanoparticles. The nature of MnO 2 nanoparticles was revealed by an absorption peak at 590 nm in a spectrophotometer (A1000). Then, these MnO 2 nanoparticles were applied to decolorize the crystal violet dye. At 0.004% dye concentration, pH 4, and concentration of MnO 2 nanoparticles of 0.005 g/L at temperatures of 50 °C, the target dye was decolorized by 91.3%. Percent reductions in COD and TOC were found to be 92.1% and 90.6%, respectively. Finally, the dye decolorization pathway was proposed based on the experimental findings.