The article explores the features of Pt(0) nanoparticle formation at the interface of nickel-aqueous solution of reagents and a similar interface containing nanoflakes of Co(OH)2. The synthesis was carried out
under Successive Ionic Layers Deposition (SILD) conditions, and solutions of Na2PtCl6, CoCl2, and NaBH4 were used as the reagents. Pt(0) nanolayers were produced on the nickel surface using Na2PtCl6 and NaBH4 solutions, and for Co(OH)2 nanolayers CoCl2 and NaBH4 solutions were used. Structural chemical
studies of the samples synthesized were performed by HRTEM, FESEM, EDX, SAED, XPS, FT-IR, and Raman spectroscopy. It was shown that Pt(0) nanolayers consist of separate nanoparticles, while Co(OH)2 nanolayers consist of nanoflakes. The main attention in the work is paid to the formation features of Pt(0) nanoparticles on a nickel surface to which a nanolayer of Co(OH)2 was previously applied. The study of the electrocatalytic properties of such samples in the hydrogen evolution reaction (HER) during water electrolysis
in the alkaline medium showed that the best properties are exhibited by nanoparticles synthesized after 20–40 SILD cycles and on nickel substrates with Co(OH)2 nanolayers applied in advance. Also, it was found
that among these samples the best properties are displayed by those containing Co(OH)2 layers synthesized after 5 SILD cycles. One of the best examples of this series was obtained from 40 SILD cycles and is characterized
by the overpotential value at 29 mV of current density at 10 mA/cm2, the Tafel slope value at 29.5 mV/dec, and high stability of these values at multiple cycle potential. It is noted that the Pt(0) nanoparticles synthesized after 40 SILD cycles are 4–8 nm in size and are located on the surface of the nanoflakes at
a distance of about 10 nm from each other for the nickel foam sample, on the surface of which a Co(OH)2 nanolayer was synthesized as a result of 5 SILD cycles. These features contribute to the formation of a set of Pt(0) nanoparticle contact points with the surface of Co(OH)2 nanoflakes, which determines the high electrocatalytic activity and stability of properties of such structures.