Spontaneous galvanic displacement of Pt nanostructures on nickel foam: Synthesis, characterization and use for hydrogen evolution reaction

In this paper we propose the use of spontaneous galvanic displacement as a promising solution to produce nickel foam electrodes functionalized with interconnected platinum nanoparticles. Scanning Electron Microscopy analyses, coupled with X-ray Energy Dispersive Spectroscopy show that, under proper conditions, we can overcome the limits of other deposition techniques, achieving a uniform Pt coverage throughout the 3D structure of the Ni foam. We show that such a condition, not deeply investigated in previous literature, turns out to be crucial for the long term stability of the electrodes under constant current stress. The amount of Pt on the Ni foam has been experimentally evaluated, obtaining optimal results with 0.015 mg cm of noble metal in a 0.16 cm thick electrode. Such a low amount corresponds to a Ni foam cost increase of less than 0.1%.