Magnetic nanoparticles decorated multi-walled carbon nanotubes by bio-inspired poly(dopamine) surface functionalization

Magnetic carbon nanotube composites were prepared by decorating magnetic Fe3O4 nanoparticles on the external surface of polydopamine (PDA)-encapsulated carbon nanotubes (CNTs/PDA) in an in situ coprecipitation method. The process involved the encapsulation of CNTs with PDA, the deposition of Fe2O3 on the CNTs/PDA surface, and the deposition of Fe3O4 on the Fe2O3-deposited CNTs/PDA surface. In this process, PDA was used as an ionic sorbent to adsorb cations, and Fe2O3 was used as seeds to induce the coprecipitation of Fe3O4. The results show that the Fe2O3 and magnetic Fe3O4 nanoparticles are uniformly distributed on the surface of CNTs, and the magnetic CNT composites display good ferromagnetic property.