Ethanol electro-oxidation on nanoworm-shaped Pd particles supported by nanographitic layers fabricated by electrophoretic deposition

Abstract

Different morphologies of nanographitic flake coatings used as catalyst supports for nanoworm-shaped palladium (Pd) were fabricated via the electrophoretic deposition (EPD) of dispersed nanographitic flakes in isopropyl alcohol. Various concentrations of magnesium nitrate hexahydrate (MNH) were used as an additive binder in the EPD process. After that palladium nanoworms were deposited by a direct sputtering on the fabricated nanographitic flake coatings. It was observed that the variation of the MNH concentration has a remarkable influence on the flake packing density of the deposited coatings and the adhesion between the nanographitic flakes and indium tin oxide (ITO) coated glass plates, thus offering a control of the aggregation of the nanographitic flakes. The morphology change of the coatings caused by MNH, which can either improve or weaken the conductivity of the fabricated coatings, has an important role in determining the performance of the Pd-sputtered samples for ethanol electro-oxidation. The sample obtained with 1 mg mL⁻¹ of MNH exhibited a high electrocatalytic activity and stability due to a high flake packing density and strong adhesion between the nanographitic flakes and ITO, and retained planar morphology of the nanographitic flakes during the EPD.