Electrochemical Behavior of Nanostructured Fe-Pd Alloy During Electrodeposition on Different Substrates

Abstract

In this work, Fe-Pd alloy films have been electrodeposited on different substrates using an electrolyte containing [Pd(NH 3) 4 ] 2 + (0.02 M) and [Fe-Citrate] 2 + (0.2 M). The influences of substrate and overpotential on chemical composition, nucleation and growth kinetics as well as the electrodeposited films morphology have been investigated using energy dispersive X-ray spectroscopy (EDS), current-time transients, scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray diffraction (XRD) patterns. In all substrates-brass, copper and sputtered fluorine doped tin oxide on glass (FTO/glass)-Fe content of the electrodeposited alloys increases by increasing the overpotential. Also the cathodic current efficiency is low due to high rate of H 2 co-reduction. Regarding the chronoamperometry current-time transients, it has been demonstrated that the nucleation mechanism is instantaneous with a typical three dimensional (3D) diffusion-controlled growth in the case of brass and copper substrates; while for FTO, the growth mode changes to 3D progressive. At a constant overpotential, the calculated number of active nucleation sites for metallic substrates is much higher than that of FTO/glass; however by increasing the overpotential, the number of active nucleation sites increases. The SEM micrographs as well as the XRD patterns reveal the formation of Fe-Pd alloy thin films with nanostructure arrangement and ultrafine grains.

The Effect of a Substrate Material on Composition Gradients of Fe-Ni Films obtained by Electrodeposition

“…Diffractograms confirmed the influence of the crystal structure of the substrate only in the case of the copper and brass. The silver substrate did not influence the crystal structure of the deposit 19,20,[29][30][31][32][33] . The effect of the substrate on the alloy's composition and its crystal structure is the correlation between the magnetic nature and the diffusion coefficient of the substrate.…”