Doping process effect of polyaniline doped with poly(styrenesulfonic acid) supported platinum for methanol oxidation

Polyaniline (PANI) is doped with poly(styrenesulfonic acid) (PSS) using doping time of 10, 60, 300, 900, and 1800 s to obtain PANI–10PSS, PANI–60PSS, PANI–300PSS, PANI–900PSS, and PANI–1800PSS films, respectively. Fourier transform infrared spectroscopy (FT-IR) results confirm that PANI is doped with PSS. X-ray photoelectron spectroscopy (XPS) results indicate that a saturated doping state is achieved when PANI dope with PSS up to 300 s. Scanning electron microscopy (SEM) images reveal that PANI doped with PSS films are composed of highly porous nanowires. Platinum (Pt) can be incorporated into PANI–10PSS, PANI–60PSS, PANI–300PSS, PANI–900PSS, and PANI–1800PSS via electrochemical deposition to obtain PANI–10PSS–Pt, PANI–60PSS–Pt, PANI–300PSS–Pt, PANI–900PSS–Pt, and PANI–1800PSS–Pt composite electrodes, respectively. Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) results indicate that Pt particles disperse more uniformly into the spatial regions of PANI–300PSS than those of other films, and the PANI–300PSS–Pt electrode provides the most active surface area of Pt in these electrodes. Cyclic voltammetry results and chronoamperometric response measurements show that the activity and stability toward methanol oxidation of the PANI–300PSS–Pt electrode are the best in these electrodes, respectively.

► PANI–PSS films are prepared using various PSS doping processes.
► XPS depicts that a saturated doping state is achieved when PANI dope with PSS up to 300 s.
► The PANI–300PSS–Pt electrode exhibits the highest current density toward methanol oxidation.
► Chronoamperograms show the stability toward methanol oxidation of PANI–300PSS–Pt electrode.