Advanced Catalytic and Electrocatalytic Performances of Polydopamine-Functionalized Reduced Graphene Oxide-Palladium Nanocomposites

A polydopamine-functionalized reduced graphene oxide (PDA-RGO)/Pd nanocomposite was synthesized by a simple wet chemical approach at room temperature. Graphene oxide (GO) was first modified with PDA by the self-polymerization of dopamine (DA) followed by the deposition of Pd nanoparticles. UV/Vis and FTIR spectroscopies confirmed the reduction of GO to RGO during the self-polymerization of DA. SEM images revealed that Pd nanoclusters were formed on both sides of the PDA-RGO sheets. The as-prepared PDA-RGO/Pd nanocomposites exhibited excellent catalytic activity in the chemical degradation of methylene blue with a reaction rate constant of 0.6028 min−1, which was 2.5-fold faster than that of the PDA/Pd catalyst without RGO. Moreover, the PDA-RGO/Pd nanocomposite also showed an outstanding electrocatalytic activity towards the electro-oxidation of paracetamol. The current response had a linear relationship to the concentration of paracetamol in the range of 0.28–100 μm with a low detection limit of 0.087 μm (S/N=3). In addition, the sensor also exhibited good selectivity for the detection of paracetamol.