Formation of Mn3O4 nanobelts through the solvothermal process and their photocatalytic property

Abstract

Hausmannite Mn3O4 nanobelts were synthesized from manganese acetate and potassium hydroxide precursors in the presence of melamine–ethanol–distill water via the reflux and solvothermal methods. X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopes confirm the composition of the as-prepared product. Field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), selected area electron diffraction (SA-ED), high resolution transmission electron microscopy (HR-TEM) and N2 adsorption-desorption isotherm results showed that the as-fabricated sample exhibits a nanosized belt-like crystal, single crystalline, tetragonal phase structure and high BET surface area. The effects of the reaction conditions such as melamine amount, solvent ratios and reaction time on the morphology of the products were studied. The band gap of the as-synthesized products was calculated via diffuse reflectance spectral analysis and their activity of catalytic oxidation was evaluated by degradation of diphenylthiocarbazone under visible-light irradiation. GC–MS instrument was used to monitor the temporal course of the catalytic reaction. The results showed that the degradation efficiency of diphenylthiocarbazone catalyzed by Mn3O4 nanobelts was higher than that which had been prepared in particle and sheet-like nanocrystals.