Browsing by Author "Butyrina, Tetyana E."

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Electrosynthesis of Ni-Fe Films With Enhanced Electrocatalytic Activity for Hydrogen Evolution From Alkaline Electrolyte
(Oles Honchar Dnipro National University, Dnipro, 2025) Sukhii, Mykhailo K.; Sknar, Iryna V.; Butyrina, Tetyana E.; Sknar, Yuri E.; Nefedov, Volodymyr G.; Polishchuk, Yuliya V.
ENG: The work is devoted to the topical issue of creating electrocatalysts for hydrogen evolution from alkaline electrolyte. The rapid development of hydrogen energy using the electrolytic method of hydrogen requires the use of cheap, resource-intensive and highly catalytic cathode materials. The most variable and flexible in control is the electrochemical method of synthesizing electrocatalysts of this type. A very promising material for cathodic hydrogen release is the Ni-Fe alloy. The limiting factor for its use is the high internal stresses that arise during its electrosynthesis. To reduce the internal stresses of Ni-Fe electrocatalyst films, sulfur-containing modifiers sodium allyl sulfonate and sodium saccharinate were used in this work, which were introduced into the methanesulfonate electrolyte of electrodeposition. It was established that increasing the concentration of sodium allyl sulfonate from 30 to 100 mmol/l leads to a decrease in internal stresses from 300 MPa to 100 MPa. The use of sodium saccharinate in a concentration of 0.5 mmol/l to 6 mmol/l contributes to a decrease in internal stresses from 300 MPa to 0 MPa. This effect of modifiers on internal stresses is associated with a change in the alloy structure due to the incorporation of sulfur and hydrocarbon residues of modifiers. It was found that the Ni-Fe alloy obtained in the presence of allyl sulfonate demonstrates high electroactivity, approaching the electroactivity of platinum. This effect is explained by an increase in defects in the crystal lattice and the presence of nickel and iron sulfide particles in the structure of the cathode material. It is recommended to carry out the electrosynthesis of Ni-Fe, as electrocatalysts for hydrogen evolution, from a methanesulfonate electrolyte containing 80–100 mmol/l of sodium allyl sulfonate in the range of current densities from 3 to 7 A/dm2.