Ni-Fe alloy nanostructured electrodes for water splitting in alkaline electrolyser. (20th August 2021)

• Record Type: Journal Article
• Authors: Buccheri, Biagio; Ganci, Fabrizio; Patella, Bernardo; Aiello, Giuseppe; Mandin, Philippe; Inguanta, Rosalinda
• Is Part Of: Electrochimica acta. Volume 388(2021)
• Publication Date: 2021-08-20
• Subjects: Alkaline electrolyzer -- Nanostructured electrodes -- Ni-Fe Alloy -- HER -- OER -- Template electrosynthesis; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2021.138588
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: 1 Ni-Fe alloy nanowire were studied as cathode and anode for alkaline electrolyzer. 2 Nanostructured arrays were obtained by template electrosynthesis method. 3 Alloy composition was controlled tuning the composition of deposition bat. 4 Electrochemical tests in KOH solution were performed at room temperature.. 5 Electrodes with a Fe of 78.95% have the best performances. Abstract: In this work, nickel-iron alloy nanostructured electrodes obtained by template electrosynthesis method are investigated for both hydrogen and oxygen evolution reactions. Electrodes consist of nanowire arrays with high surface area that are able to ensures a high electrolytic activity. To obtain different alloy compositions, the concentration of the elements in the deposition baths is appropriately tuned. Results show that the composition of nanowires does not change linearly with the composition of deposition bath but are richer in Fe. Nanostructured electrodes are tested as both cathodes and anodes in 30 wt% KOH aqueous solution, at room temperature to determine the best alloy composition. In all electrochemical tests, the electrodes that performed best are those with iron content of 78.95 at%. Particularly, the results are very promising for the oxygen evolution reaction, with a Tafel's slope of 40 mV and a potential of 1.532 V vs. RHE after 6 h at constant current of 50 mA cm −2 . Besides, preliminary tests in 0.5 M NaCl alkaline aqueous solution are also reported showing very promising results. Graphical abstract: Image, graphical abstract