Nanostructured Ni-Based Alloys as Electroactive Porous Transport Layers for Anion-Exchange Membrane Water...

Development of efficient, durable, and sustainable materials for anion-exchange membrane water electrolyzers (AEMWEs) is pivotal for producing scalable green hydrogen. This study investigates the use of helium plasma irradiation to fabricate self-supported nanostructures on nickel-based porous transport layers (PTLs), such as nickel, stainless steel, Inconel, and Hastelloy, and evaluates their performance as anodes in AEMWEs. Nanostructuring the PTLs improves their surface properties, such as increased hydrophilicity and higher surface area, leading to an improvement in performance. The Hastelloy PTL as the anode features the highest activity among the tested materials, and an AEM cell using nanostructured Hastelloy PTL as an anode achieves 1 A cm^-2 at 1.79 V at 50 °C. Furthermore, the cell also shows excellent stability at 1 A cm^-2 for 500 h with a minimal degradation rate of ∼25 μV h^-1, indicating the robustness of this material. At elevated temperatures (∼80 °C), the electrolyzer also achieves current densities of ∼2.4 A cm^-2 at 1.8 V, aligning closely with the technical targets for water electrolyzers. Going forward, the current findings indicate helium plasma treatment as a versatile and eco-friendly approach for fine-tuning the surface morphology of a broad range of materials that can be employed to scale up next-generation AEMWE systems.