A novel magnetic manganese oxide halloysite composite by one-pot synthesis for the removal of methylene blue from aqueous solution

In this study, the magnetic manganese oxide halloysite composite was prepared by one-pot synthesis method. The methylene blue (MB) removal performance was synergistically enhanced by both adsorption capacity and Fenton-like degradation and the used particles can be separated by using an external magnetic field for the next regeneration. The prepared samples were characterized by XRD, FTIR, SEM, TEM, XPS, magnetic measurement and zeta potential. Characterization results illustrate that both Fe3O4 and MnO2 were successfully introduced and relatively well-distributed on the surface of halloysite nanotubes. A perfect magnetization property was obtained. In the removal process, the prepared sample exhibited the maximum adsorption capacity of methylene blue about 96.47 mg/g. The adsorption behavior results indicate that the pseudo-second-order model is more suitable to describe this process and MB adsorption was better described with the Langmuir model. After the removal reaction, the stable structure of the sample was proved by XPS and SEM. Moreover, the stable removal performance of the sample in the multiple cycles of regeneration indicates that the magnetic manganese oxide halloysite composite is an effective material for the methylene blue removal.