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Dynamic Hydrogen Bubble Templating of Ni electrodes (NiDHBT) is applied to form fractal macroporous structures and their properties towards oxygen evolution reaction (OER) is assessed. Upon varying Ni electrodeposition conditions, morphological features with percolating porosity were finely tuned and electrochemical activity towards O2 evolution reaction (OER) in 1M KOH were enhanced. As demonstrated by cyclic voltammetry, NiDHBT electrochemical features displayed a tremendous increase (x 250) of the electrochemically active Ni surface atoms, with strong mechanical adherence to the underlying substrate. Under constant electrolysis (0.25 A cm-2), OER potentials remained stable and occurred at lower potentials (shifted by ca. 300 mV) as compared to a bare Ni plate. Contact angle measurements confirm the super-aerophobic nature of the fractal Ni films, which leads to fast and sustainable release of O2 bubbles during potentiostatic measurements. Due to the versatility of the DHBT method, fractal Ni-based, e.g. NixFe1-x, electrodes for use in advanced electrolysis cell configurations can be envisioned, to further examine transport enhancement in relevant industrial systems and its tolerance to commercial alkaline solutions. |
