Conducting Polymer-Based Electrode with Magnetic Behavior: Electrochemical Synthesis of Poly(3-thiophene-acetic-acid)/Magnetite Nanocomposite Thin Layers

Polythiophene−magnetite composite layers have been prepared through the electropolymerization of 3-thiophene-acetic-acid in the presence of Fe 3 O 4 nanoparticles in nitrobenzene. Stabilization of magnetite in this organic medium could be achieved by the reaction between surface −OH groups of the nanoparticles and the −COOH function of the monomers. Fourier transformed infrared spectroscopic (FT-IR) measurements evidenced the chemisorption of the monomer on the surface of the nanoparticles. By modifying the amount of iron-oxide in the polymerization solution, the inorganic material content of the layer could be increased up to 80 m/m%. Electrochemical results, including data obtained by electrochemical quartz crystal microbalance (EQCM), proved that the presence of Fe 3 O 4 did not influence the redox properties of the polymeric film. In the presence of magnetite, an extraordinary microstructure can be detected, where the self-assembling magnetic component strongly determines the morphology of the composite, leading to band formation of ∼1 μm width. This new modified electrode, incorporating such a large amount of Fe 3 O 4, may be used in magnetic electrocatalysis.