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

Abstract

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 (H 2 O 2 ) 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 × 10 8 cm 3 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 H 2 O 2 , and should be useful in practical H 2 O 2 sensors.