Synthesis and characterization of poly(3,4-ethylenedioxythiophene) functionalized graphene with gold nanoparticles as a potential oxygen reduction electrocatalyst

Abstract

The synthesis of gold nanoparticles decorated poly(3,4-ethylenendioxythiophene) loaded on reduced graphene oxide (AuNPs/PEDOT/rGO) was carried out by one-pot method as a potential cathode catalyst in fuel cells. The composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Raman spectroscopy, Brunauer-Emmett-Teller (BET) and thermogravimetric analysis (TGA). From the SEM and TEM; it was found that AuNPs and PEDOT have a uniform distribution on rGO sheets. Meanwhile, FTIR and Raman spectroscopy results confirmed the existence of vibrational and adsorption bond of PEDOT on rGO sheets, while XRD pattern revealed the formation of AuNPs/PEDOT/rGO composite by characteristic of crystallographic structure. The nitrogen adsorption isotherm study indicated that the composites have both mesopores and macropores particle size. The analysis of thermogravimetric showed the synthesized composites are stable, where the decomposition step was below than 400 °C with a slightly mass loss. For the fabrication of electrode, the composite's suspension was drop-casted on glassy carbon electrode (GCE) and characterized using cyclic voltammetry (CV) technique and electrochemical impedance spectroscopy. AuNPs/PEDOT/rGO modified GCE exhibits better electron transfer, good capacitive and control-diffuse behaviour. The electrocatalytic activity toward oxygen reduction reaction was investigated by cyclic voltammetry in the presence of O2-saturated 0.1 M KOH solution. The results demonstrated that AuNPs/PEDOT/rGO/GCE has a good response toward catalytic of O2. Therefore, this work gives support that the AuNPs/PEDOT/rGO composite has a potential for cathode materials in fuel cells.