Preparation of Fe3O4/α-MnO2 Magnetic Nanocomposites for Degradation of 2,4-DCP through Persulfate Activation

Abstract

In this study, Fe3O4 magnetic nanoparticles (MNPs) were loaded on α-MnO2 nanowires using an improved hydrothermal synthesis method combined with an ultrasonic coprecipitation method, the loading ratio was optimized, the efficiency of the prepared Fe3O4/α-MnO2-activated persulfate (PS) system for the degradation of 2,4-dichlorophenol (2,4-DCP) was investigated, and the effects of PS concentration, Fe3O4/α-MnO2 magnetic nanocomposites (MNCs) dosage, pH value and initial pollutant concentration on the degradation of 2,4-DCP were investigated. The results showed that when the initial concentrations of 2,4-DCP, PS, and Fe3O4/α-MnO2 MNCs were 100 mg/L, 30 mmol/L, and 0.4 g/L, the degradation rate of 2,4-DCP reached 96.3% after 180 min of reaction at 30 °C under a neutral condition, and the fitting results showed that the degradation of 2,4-DCP by the Fe3O4/α-MnO2-activated PS system conformed to quasi-first-order kinetics. The degradation of 2,4-DCP by different Fe3O4/α-MnO2-activated PS systems was compared, and a possible PS activation mechanism was proposed. The Fe3O4/α-MnO2 MNCs exhibited excellent reusability, and by introducing Fe3O4/α-MnO2 MNCs as the PS activator into the advanced oxidation process (AOP) system, the electron transfer of Mn(III/IV) and Fe(III/II) on the surface of MNCs was realized, thus greatly improving the reaction efficiency.

Potential of MnO2‐based composite and numerous morphological for enhancing supercapacitors performance

“…SEM images of (A) nanowire, 131 (B) nanoflower, 132 (C) urchin‐like, 133 (D) nanorods, 134 (E) staghorn coral shape, 135 (F) nanorods, 136 (G) flower‐like, 136 (H) honeycomb‐like, 137 and (I) nanofiber 138 …”

“…Figure 4 shows various MnO 2 morphologies to create supercapacitors and reveals an electrochemical performance improvement whenever morphological alterations are made from one form to another. 131 (B) nanoflower, 132 (C) urchin-like, 133 (D) nanorods, 134 (E) staghorn coral shape, 135 (F) nanorods, 136 (G) flower-like, 136 (H) honeycomb-like, 137 and (I) nanofiber. 138…”