The “rolling up” effect of platinum layer obtained on nickel surface by interaction with solution of H$_2$PtCl$_6$ and its electrocatalytic properties in hydrogen evolution reaction during water electrolysis in alkaline medium

We have shown for the first time that a platinum layer has been obtained on the surface of nickel foil as a result of Galvanic Replacement Reaction (GRR) when interacting with an aqueous solution of H$_2$PtCl$_6$, during drying in air, partially rolling up into incompletely formed microscrolls with a unique 3D morphology. Analysis of the wall of these microscrolls by FESEM, TEM, HR-TEM, and SAED methods showed that they are porous and formed by platinum nanocrystals with sizes of 5 – 10 nm, and their packing density over the wall thickness differs. Nickel foil samples with the layer of platinum microscrolls deposited on their surface exhibit high electrocatalytic activity in hydrogen evolution reaction (HER) during water electrolysis in the alkaline medium. In particular, the overpotential value is 32 mV and the Tafel slope is 32.5 mV/dec for an electrode with the platinum layer with a thickness of 120 – 140 nm.