Abstract
Poly(ANI-co-Py)/Pd composite was prepared by electrochemical polymerization from a mixed monomer solution in 0.5 M LiClO4/acetonitrile. The prepared composite was investigated as a catalyst for the electrooxidation of hydrazine by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Scanning electron microscope (SEM) photos showed that Pd particles are uniformly distributed over the rough copolymer surface. The electrocatalytic activity of the prepared composite was compared with those of individual polymers composites, polyaniline/Pd (PANI/Pd) and polypyrrole/Pd (PPY/Pd). It was proved that the copolymerization enhanced the electrocatalytic activity toward hydrazine oxidation as indicated by the increased oxidation peak current in CV and the reduced charge transfer resistance determined by EIS. The optimum pH for performing the hydrazine oxidation by the proposed catalyst is 6. Kinetic study shows that the process is diffusion-controlled with a diffusion coefficient value of 1.94 10-4 cm2∙s-1. A linear calibration curve was obtained between 3 mM and 0.01 M with a sensitivity value of 98.31 μA∙mM-1 and a limit of detection (LOD) value of 0.38 μM. The presented composite showed good stability, reproducibility, and selectivity for hydrazine oxidation.