Preparation and characterization of palladium/polypyrrole-reduced graphene oxide/foamed nickel composite electrode and its electrochemical dechlorination of triclosan

In this study, a new composite electrode of palladium (Pd) nanoparticles dispersed on polypyrrole-reduced graphene oxide (PPy-rGO) loaded on foam-nickel was achieved by galvanostatic method. Characterization of structures, morphology and crystallinity of the synthesized materials were investigated by scanning electron microscopes (SEM), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Raman spectroscopy and electrochemical impedance spectroscopy (EIS). The results of XPS and XRD demonstrated Pd showed primarily as Pd0. From SEM and TEM results, we had seen that Pd nanoparticles were dispersible well on the composite electrode. Raman spectroscopy was used to show the state of graphene oxide and further demonstrated that PPy and rGO had existed of on the foam Ni matrix. The data of EIS also suggested the charge transfer of the new composite electrode decreased compared to Pd/PPy/foam-Ni and PPy/foam-Ni composite electrodes. The effect of the electropolymerization potential on Pd/PPy-rGO/foam-Ni electrode for removing triclosan (TCS) was examined. It was found that the removal efficiency of TCS on the composite electrode could reach 100% at electropolymerization potential of 0.7 V and reaction time of 100 min. Keywords: Pd/PPy-rGO/foam-Ni electrode, Triclosan, Electrocatalytic hydrodechlorination, Potentiostatic electropolymerization, Applied potential