biostudies-literatureUnknown6(9)Foroughi FIn this investigation, we report on the development of a method for activating polycrystalline metallic nickel (Ni(poly)) surfaces toward the hydrogen evolution reaction (HER) in N₂-saturated 1.0 M KOH aqueous electrolyte through continuous and pulsed ultrasonication (24 kHz, 44 ± 1.40 W, 60% acoustic amplitude, ultrasonic horn). It is found that ultrasonically activated Ni shows an improved HER activity with a much lower overpotential of -275 mV vs RHE at -10.0 mA cm^-2 when compared to nonultrasonically activated Ni. It was observed that the ultrasonic pretreatment is a time-dependent process that gradually changes the oxidation state of Ni and longer ultrasonication times result in higher HER activity as compared to untreated Ni. This study highlights a straightforwACS applied energy materials4520-4529https://www.ebi.ac.uk/biostudies/studies/S-EPMC10170477biostudies-literatureIn Situ Sonoactivation of Polycrystalline Ni for the Hydrogen Evolution Reaction in Alkaline Media.PMC10170477Foroughi FPollet BGCoutanceau CTintor MSunde SJerkiewicz GFaid AYfalseIn Situ Sonoactivation of Polycrystalline Ni for the Hydrogen Evolution Reaction in Alkaline Media.In this investigation, we report on the development of a method for activating polycrystalline metallic nickel (Ni(poly)) surfaces toward the hydrogen evolution reaction (HER) in N₂-saturated 1.0 M KOH aqueous electrolyte through continuous and pulsed ultrasonication (24 kHz, 44 ± 1.40 W, 60% acoustic amplitude, ultrasonic horn). It is found that ultrasonically activated Ni shows an improved HER activity with a much lower overpotential of -275 mV vs RHE at -10.0 mA cm^-2 when compared to nonultrasonically activated Ni. It was observed that the ultrasonic pretreatment is a time-dependent process that gradually changes the oxidation state of Ni and longer ultrasonication times result in higher HER activity as compared to untreated Ni. This study highlights a straightforw2023-01-01T00:00:00Z2023 May2025-04-04T13:51:06.054Z2025-04-04T13:51:06.054ZS-EPMC101704773718124710.1021/acsaem.2c02443