The study on the application of solid-state method for synthesizing the polyaniline/noble metal (Au or Pt) hybrid materials

Abstract

The solid-state method was applied for synthesizing polyaniline (PANI)/noble metal hybrid materials with the presence of HAuCl ₄·4H ₂O or H ₂PtCl ₆·6H ₂O in the reaction medium. The structure, morphology, and electrochemical activity of the composites were characterized by Fourier transform infrared (FTIR) spectra, UV-visible (vis) absorption spectra, energy dispersive spectrum (EDS), X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and cyclic voltammetry. The results from FTIR and UV-vis spectra showed that the oxidation degree and doping level of the PANI in composites can be influenced by HAuCl ₄·4H ₂O and H ₂PtCl ₆·6H ₂O. The EDS data demonstrated that the composites contain a certain amount of Au (or Pt) element. XRD analysis indicated the presence of crystalline-state Au particles in PANI matrix prepared from the presence of HAuCl ₄·4H ₂O and revealed that the H ₂PtCl ₆·6H ₂O cannot be converted into metal Pt. The TEM and SEM images implied that the Au particles did exist in the polymer matrix with the size of about 20 nm. The enzymeless H ₂O ₂ sensor constructed with PANI/Au composite from the presence of HAuCl ₄·4H ₂O showed a short response time (within 5 s) and displayed an excellent performance in wide linear range.