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

Abstract Magnetic carbon nanotube composites were prepared by decorating magnetic Fe 3 O 4 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 Fe 2 O 3 on the CNTs/PDA surface, and the deposition of Fe 3 O 4 on the Fe 2 O 3 -deposited CNTs/PDA surface. In this process, PDA was used as an ionic sorbent to adsorb cations, and Fe 2 O 3 was used as seeds to induce the coprecipitation of Fe 3 O 4 . The results show that the Fe 2 O 3 and magnetic Fe 3 O 4 nanoparticles are uniformly distributed on the surface of CNTs, and the magnetic CNT composites display good ferromagnetic property.