Dealloying-Driven Fabrication of Nanoporous Nickel Films for Energy-Related Applications
Ahmed Abd El Aziz, Alyaa Bakr, Randa AbdelkarimObjectives
Although dealloying is typically a destructive form of corrosion, its underlying science can be harnessed to fabricate nanoporous films. This process involves the selective leaching of the active element from an alloy, leaving behind the noble component. Consequently, this method offers a simple strategy for fabricating nanoporous catalysts optimised for hydrogen production.
Material and Methods
Nano porous nickel-based film was fabricated using the dealloying technique; the fabrication process involved three steps: electrodeposition of zinc followed by a heat treatment process and then electrochemical dealloying of the active zinc. SEM and EDX analysis were performed after each step of the fabrication process. XRD analysis revealed the existence of NiZn alloy in the dealloyed films.
Results
It was found that increasing the duration of electrodeposition of zinc leads to an increase in the thickness as well as the average pore diameter of the nonporous nickel film. The nickel films presented an average thickness of 14 μm and an average pore diameter of 936 nm. The electrocatalytic activity for the hydrogen evolution reaction (HER) was measured for the film, and the results were compared to those of a smooth nickel substrate.
Conclusion
The nanoporous nickel films exhibited much higher electrocatalytic activity for the HER than smooth nickel. The overpotential for hydrogen evolution at room temperature for samples electrodeposited for 60 min was about -0.9 mV. These findings support the production of green hydrogen as a fuel for future energy systems.