A novel ferrocene-containing aniline copolymer: its synthesis and electrochemical performance

Abstract

A novel ferrocene-containing aniline, 6-(2-amino-phenol-9H-yl)-hexyl ferrocenecarboxylate (AnFc) was synthesized via the hydrogenation of 6-(2-nitro-phenol-9H-yl)-hexyl ferrocenecarboxylate (NPFc). Then, the homopolymer of AnFc (PAnFc), copolymers of aniline and AnFc (P(An-co-AnFc)), and polyaniline (PAn) were prepared using a chemical oxidative polymerization process. The structure, morphology, and electrochemical properties of the prepared polymers were characterized by Fourier transform infrared spectroscopy (FTIR), ultraviolet visible spectroscopy (UV-vis), scanning electron microscopy (SEM), cyclic voltammograms (CV) and galvanostatic charge–discharge tests. The results demonstrated that the AnFc functionalized monomer and the corresponding polymer derivatives have been synthesized successfully, and the introduction of the novel functionalized ferrocene-based aniline obviously affected the spectral characteristic, morphology and electrochemical characteristics of the electro-active polymers obtained, as well as its charge migration along the polymer backbone. In addition, the charge–discharge tests showed that P(An-co-AnFc) improved the discharge plateau in the potential range of about 3.0–4.0 V and with an acceptable initial discharge specific capacity of 104.9 mA h g⁻¹ for P(An-co-AnFc) (5 : 1 ([An]/[AnFc])) (compared with 108.2 mA h g⁻¹ for PAn). Furthermore, P(An-co-AnFc) exhibited an even more improved cycling stability than that of PAn, and after 30 cycles the discharge capacity of P(An-co-AnFc) (3 : 1 ([An]/[AnFc])) still maintained 76.3% of the capacity obtained during the initial cycle.