Platinum palladium and bimetallic Pt-Pd nanoparticles synthesized by pulsed laser ablation for electro-sorption of hydrogen in alkaline electrolyte

Green and sustainable production of hydrogen by water electrolysers is expected as one of the most promising ways for the industrial decarbonisation and to satisfy the ever-growing demand of renewable energy production and storage. Hydrogen evolution reaction in alkaline electrolyte is preferable as an industrial point of view, as it does not require the more expensive proton exchange membranes required in an acid environment. Unfortunately, hydrogen evolution reaction in alkaline electrolyte is still challenging, due to its slow kinetic. In this work we propose new nanoelectrode arrays for high Faradaic efficiency of the electro-sorption reaction of hydrogen in alkaline electrolyte. Platinum or palladium or bimetallic Pt80Pd20 (wt.%) nanoparticles (NPs) were fabricated by nanosecond pulsed laser ablation in aqueous environment. Nanoelectrode arrays were obtained by casting onto graphene paper the water based suspension of NPs. Moreover, this work comparatively describes the effects of 0.7 μm thin films of perfluoro-sulfonic ionomer surrounding the NPs. The thin film of ionomer acts as inexpensive membrane between metal electro-catalyst and the electrolyte. Thin film of ionomer produces a significant modification in the material morphology, as well as in the nanoparticles dispersion and electrochemical performance. The NPs-GP systems have been characterized by field emission scanning electron microscopy, Rutherford backscattering spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, cyclic voltammetry, and galvanostatic charge-discharge cycles. State of the art competitive Faradaic efficiency up to 86.6% and hydrogen storage capacity up to 6 wt.% have been obtained by the Pt80Pd20 system.