Superparamagnetic NiFe₂O₄ particles on poly(3,4-ethylenedioxythiophene)-graphene: Synthesis, characterization and their excellent microwave absorption properties

The ternary nanocomposites of poly(3,4-ethylenedioxythiophene), graphene and NiFe₂O₄ (PEDOT-GN-NiFe₂O₄) were synthesized via a two-step method, in situ polymerization of poly(3,4-ethylenedioxythiophene) in the first step and followed by the crystallization of NiFe₂O₄ particles in the second step. The ternary nanocomposites were characterized by XRD, TEM, XPS, Raman spectroscopy, TG and VSM. TEM results indicated that NiFe₂O₄ particles ranged from 10 to 15nm uniformly dispersed on PEDOT-GN. The investigation of the electromagnetic absorbability reveals that the ternary nanocomposites exhibit excellent microwave absorption properties and wide absorption bandwidths. When the thickness is 2mm, the maximum reflection loss is -45.4dB at 15.6GHz and the absorption bandwidths with the reflection loss below -10dB and -20dB are 4.6GHz and 1.7GHz, respectively. Compared to PEDOT-GN, GN-NiFe₂O₄ and PEDOT-NiFe₂O₄, the enhanced microwave absorption properties of PEDOT-GN-NiFe₂O₄ are due to the improved impedance matching and the enhanced interfacial effects. Furthermore, our development strategy provides a feasible method to obtain ternary nanocomposites based on conducting polymers, graphene and magnetic particles.