Pt nanoparticles synthesized by successive ionic layers deposition method and their electrocatalytic properties in hydrogen evolution reaction during water splitting in the acidic medium

The paper explores the possibilities of the successive ionic layers deposition (SILD) nanotechnology for Pt nanoparticle synthesis. It is shown that the SILD nanotechnology, which is based on successive treatment of appropriate substrates in solutions of a platinum complex compound and a reducing agent, is effective for controlled Pt0 nanoparticles formation on the substrate surface. The Pt nanoparticles synthesized using Na2PtCl6 and NaBH4 precursors are characterized. It is found that the concentration and size of the Pt0 nanoparticles deposited on the titanium foil surface can be controlled by the number of deposition cycles. It is established that the size of the Pt nanoparticles depends on the synthesis conditions and varies from 3.3 nm to 10.0 nm for samples synthesized as a result of 10–40 SILD cycles. A model explaining Pt nanoparticle growth during SILD is suggested. It is shown that the nanoparticles obtained exhibit electrocatalytic properties in the hydrogen evolution reaction during acidic water electrolysis. In a series of samples synthesized using 10–40 SILD cycles, the best electrochemical characteristics are demonstrated by the sample obtained after 20 deposition cycles: its overpotential value is 44 mV and the Tafel slope is 30.4 mV/dec.