Electrochemical Synthesis of Palladium–Selenide Coatings

Abstract

This research explores the electrochemical synthesis of Pd-Se coatings from acidic chloride solutions using cyclic voltammetry to understand the reaction mechanism. The study examines how the applied potential and electrolyte composition affect the coatings’ properties. Energy-dispersive X-ray spectroscopy and X-ray diffraction were used for elemental and phase analyses, respectively, while a scanning-electron microscope assessed the surface morphology. The findings indicate that the deposition potential significantly affected the coatings’ properties, altering the selenium-deposition reaction’s mechanism and the coatings’ elemental and phase composition and morphology. As the potential decreases, the mechanism transforms, influencing the elemental and phase compositions and the coatings’ morphology. The feasibility of co-depositing palladium with selenium in varying stoichiometric ratios and diverse phase compositions was confirmed. The post-heat-treatment-phase analysis highlighted a mix of intermetallic phases, with Pd17Se15 being predominant in the solutions with 1:2 and 1:1 palladium-to-selenium ratios. Electrolysis at lower potentials and from electrolytes with higher palladium-to-selenium ratios results in pure palladium coatings.