Fabrication and characterization of nanostructured Ni–IrO2 electrodes for water electrolysis

• Nanostructured Ni electrodes with IrO2 catalyst were prepared by electrodeposition.
• Deposition method influences both electrode morphology and catalytic activity.
• Galvanostatic deposition produces the best nanostructured electrodes.
• Performance of alkaline electrolyzers with different anode electrodes was evaluated.
• Nanostructured Ni electrodes appear ideal for application in industrial electrolyzers.

Nanostructured Ni–IrO2 electrodes were fabricated by electrodeposition in a two-step procedure: first arrays of nickel nanowires (NWs) were electrodeposited within pores of polycarbonate (PC) membranes, then iridium oxide nanoparticles were deposited on the Ni metal after membrane dissolution, for improving the catalytic activity. The aim was to compare performance of these electrodes with traditional ones consisting of Ni film. Different methods of deposition of the IrO2 electrocatalyst were investigated and the effect on electrodes stability and activity is discussed. Despite a low coverage of Ni NWs by the electrocatalyst, results indicate a faster kinetics of O2 evolution in 1 M KOH solution and an improvement of performances for electrolysers having a nanostructured anode.

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