The electrocatalytical reduction of m-nitrophenol on palladium nanoparticles modified glassy carbon electrodes

Palladium nanoparticles modified glassy carbon electrodes (Pd/GC) were prepared via the electrodeposition of palladium on a glassy carbon (GC) electrode using cyclic voltammetry in different sweeping potential ranges. The scanning electron microscope images of palladium particles on the GC electrodes indicate that palladium particles with diameters of 20–50 nm were homogeneously dispersed on the GC electrode at the optimal deposition conditions, which can effectively catalyze the reduction of m-nitrophenol in aqueous solutions, but their catalytic activities are strongly related to the deposition conditions of Pd. The X-ray photoelectron spectroscopy spectra of the Pd/GC electrode confirmed that 37.1% Pd was contained in the surface composition of the Pd/GC electrode. The cyclic voltammograms of the Pd/GC electrode in the solution of m-nitrophenol show that the reduction peak of m-nitrophenol shifts towards the more positive potentials, accompanied with an increase in the peak current compared to the bare GC electrode. The electrocatalytic activity of the Pd/GC electrode is affected by pH values of the solution. In addition, the electrolysis of m-nitrophenol under a constant potential indicates that the reduction current of m-nitrophenol on the Pd/GC electrode is approximately 20 times larger than that on the bare GC electrode.

► The deposition of palladium on a GC electrode was performed by cyclic voltammetry.
► SEM images showed palladium nanoparticles deposited on a glassy carbon (GC) electrode.
► The Pd/GC electrode can effectively catalyze m-nitrophenol in aqueous media.
► The reduction of m-nitrophenol on the Pd/GC electrode depended on potential and pH.
► XPS spectra of the Pd/GC electrodes demonstrated the presence of palladium.