Formation of Fe3O4@C/Ni microtubes for efficient catalysis and protein adsorption

Abstract

In the recent years, the fabrication of functional nanostructures with multicomponent has received considerable attention due to their exceptional properties. Herein, we report a facile approach for the preparation of Fe₃O₄@C/Ni microtubes, which could be used as both a catalyst and the adsorbents. During the synthetic process, a layer of nickel ion-doped polydopamine (PDA-Ni²⁺) was polymerized in situ on the surface of the MoO₃@FeOOH by an extended stöber method using MoO₃ microrods as the sacrificing templates. Notably, the PDA-Ni²⁺ coating and the removal of the MoO₃ cores were carried out simultaneously during the coating of the PDA-Ni²⁺ in an ammonia solution. Then the prepared FeOOH@PDA-Ni²⁺ microtubes were converted to Fe₃O₄@C/Ni hybrid microtubes through a pyrolysis with a thermochemical reduction process. The resulting Fe₃O₄@C/Ni hybrid microtubes were used as a novel catalyst towards the reduction of 4-nitrophenol (4-NP) in the presence of NaBH₄. Moreover, they also exhibited highly selective adsorption on His-rich proteins (BHb). Moreover, the Fe₃O₄@C/Ni hybrid microtubes can be conveniently separated by an external magnetic field due to the presence of Ni and Fe₃O₄. Furthermore, they show good cyclic stability, which is important for the practical applications.