The effects of hydrothermal holding time and dispersant addition on structure and catalytic activity of MnFe2O4 nanoparticles

Abstract

In this study, the ferrite spinel MnFe2O4 nanoparticles were synthesized by hydrothermal method, and then were used to induce persulfate (PS) to degrade azo-dye Direct Blue 15 (DB15). The influences of holding time and Polyethylene glycol (PEG) addition during synthesis process on the MnFe2O4 structure and catalytic activities were also investigated and discussed systematically. X-ray diffraction (XRD), Fourier Transformed Infrared Spectrometer (FTIR), Transmission electron microscopy (TEM) and energy dispersive spectrometer (EDS) were used to characterize the samples structure and morphology. The results indicated that MnFe2O4 material was successfully synthesized, and PEG was successfully covered on the MnFe2O4 when PEG was added into synthesized process. MnFe2O4 activated persulfate process has significant efficiency on DB15 degradation. The decolorization efficiency of DB15 increased firstly and decreased later as action time increased. When the MnFe2O4, synthesized at 180 °C, 12 h, was used, the decolorization efficiency of DB15 can reach 99.1% within 30 min. Moreover, the additives of PEG that introduced during the MnFe2O4 preparation also have great effects on the DB15 decolorization efficiency.