Bifunctional manganese ferrite nanoparticles: Tuning their efficiency for aniline polymerization and polyaniline nanocomposites for boosting adsorption of organic dyes

The uniqueness of this work is the comparison of manganese ferrites/polyaniline (MnxFe3 - xO4/PANI) produced using K2S2O8 as an oxidant for aniline with the efficacy of spinel manganese ferrite with various Mn2+ ratios for the polymerization of aniline. The structural and morphological properties of the nanocomposites were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and Brunauer-Emmett-Teller (BET) techniques. XRD results confirmed the formation of a single-phase cubic spinel structure with a lattice constant of approximately 8.3 angstrom. The surface enriched by Mn2+ exhibited an enhanced valence of +3 and +4, increased lattice oxygen content, facilitated ferrite reduction, and improved the oxidative performance of Fe3+. The saturation magnetization decreased with an increase in Mn+2 ratios and PANI contents. The nanocomposites exhibited excellent adsorption of Lanaset Brown B dye, which was investigated as a model textile dye. Various adsorption capacities (q(max)) for the nanocomposites were calculated in a range of 122.39-215 mg/g, depending on the synthesis conditions. Optimization parameters, such as pH, adsorbent dose, and initial concentration, as well as reusability, were described. The Langmuir isotherm is a better model for describing the adsorption process of the nanocomposites. An evaluation of thermodynamic parameters suggests the sorption process is feasible, spontaneous, and endothermic.

Automated summary

This study compares the efficacy of manganese ferrite/polyaniline (MnxFe3 - xO4/PANI) with spinel manganese ferrite in the polymerization of aniline using K2S2O8 as an oxidant. Various techniques were used to characterize the structural and morphological properties of the nanocomposites. The results showed that the Mn2+-enriched surface enhanced the oxidative performance of Fe3+. The nanocomposites also exhibited excellent adsorption capacity for Lanaset Brown B dye, and the adsorption process was described and evaluated in detail.