Fe-Mn-Si-O and Fe-Mn-Si-O/multi walled carbon nanotubes: synthesis, characteristics, adsorption and catalytic behavior

Abstract

The mixed metal oxide nanostructures (Fe-Mn-Si-O) and Fe-Mn-Si-O/Multi walled carbon nanotubes (Fe-Mn-Si-O/MWCNT) were synthesized by a hydrothermal approach. The prepared samples were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Fe-Mn-Si-O has efficient removal of methylene blue (MB) and rhodamine b (RhB) from aqueous solution and both prepared compounds have an effective catalytic property in styrene oxidation reaction. In the process of exploring the adsorption conditions, the isotherms were found to be well fitted by Langmuir and Freundlich models. Moreover, the thermodynamic of RhB and MB adsorption was also studied. To investigate the adsorption mechanism, it was found that the adsorption kinetics of MB and RhB onto the Fe-Mn-Si-O surface was best described by the pseudo second-order model. In the next step, the catalytic behavior of Fe-Mn-Si-O and Fe-Mn-Si-O/MWCNT were studied in the styrene oxidation reaction, which yielded only benzaldehyde. Highlights Novel Fe-Mn-Si-O and Fe-Mn-Si-O/MWCNT were prepared by hydrothermal method. Fe-Mn-Si-O and Fe-Mn-Si-O/MWCNT were applied as catalyst in the styrene oxidation reaction The adsorption of MB and RhB was studied on the Fe-Mn-Si-O. Fe-Mn-Si-O and Fe-Mn-Si-O/MWCNT showed excellent behavior in catalytic reactions.