نوع مقاله : علمی و پژوهشی
عنوان مقاله English
نویسندگان English
In this study, Ni–Co–P alloy coatings were fabricated via the electroless deposition method on a copper substrate using both alkaline (pH = 8.5) and acidic (pH = 4.5) baths with varying cobalt chloride concentrations (2–10 g L⁻¹). The electrocatalytic performance of these coatings toward the hydrogen evolution reaction (HER) was evaluated. Chemical composition analysis revealed that the alkaline bath exhibited a higher cobalt incorporation efficiency, and the cobalt content in the CH10 coating (prepared in the alkaline bath containing 10 g L⁻¹ cobalt chloride) reached its maximum value, while the phosphorus content remained independent of cobalt concentration. In 1.0 M potassium hydroxide solution, the CH10 coating showed the lowest overpotential of 132 mV vs. RHE at a current density of 10 mA.cm-2. To further enhance performance, a heat-treatment process was applied, resulting in the formation of a composite structure containing transition metal phosphides (CH10-HT). The CH10-HT sample exhibited the best electrocatalytic performance, with an overpotential of 155 mV vs.RHE at a current density of 100 mA.cm-2 . Stability tests, including cyclic voltammetry (1000 cycles), stepwise chronopotentiometry, and 100-hour chronoamperometry, confirmed the excellent electrochemical stability of the catalyst, with more than 96.5% of the initial activity retained. Overall, the results demonstrate that controlling the deposition bath conditions and applying post-heat treatment play crucial roles in enhancing the electrocatalytic performance of Ni–Co–P coatings.
کلیدواژهها English
