A facile electrosynthesis method for the controllable preparation of electroactive nickel hexacyanoferrate/polyaniline hybrid films for H2O2 detection

Electroactive hybrid films with cubic nickel hexacyanoferrate/polyaniline (NiHCF/PANI) were synthesized on carbon nanotubes (CNTs) modified platinum electrodes by a facile one-step electrosynthesis method using cyclic voltammetry (CV). The morphologies and structures of the as-prepared NiHCF/PANI/CNTs films were characterized using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR), respectively. Due to the introduction of CNTs with carboxyl groups, an acidic micro-environment was provided for the nitrogen atoms in the PANI chains, which could maintain its electroactivity in neutral aqueous solutions. The hybrid films were applied for hydrogen peroxide (H2O2) detection and showed synergy and higher electrocatalytic activity with a higher sensitivity, a faster response time and a lower detection limit. It was found that detection sensitivity could be regulated by controlling the time of CV of electrosynthesis during the preparation of the hybrid film. A catalytic rate constant of 1.29 × 108 cm3 mol−1 s−1 was obtained from an investigation of the kinetics of the catalytic reaction. SEM images showed that the cubic composite nano-particles of PANI and NiHCF were formed and distributed uniformly on the CNTs. The hybrid film prepared had good stability and reproducibility in the detection of H2O2, and should be useful in practical H2O2 sensors.