Hydrogen-induced superabundant vacancies in electrodeposited Fe–C alloy films

In Situ Analysis of the Thermal Evolution of Electrodeposited Fe-C Coatings

“…Previous studies of Fe-C coatings refer to an iron-sulfate electrolyte, which was optimized to resist the oxidation of Fe 2+ to Fe 3+ by the addition of a carboxylic acid that also acts as a buffer, carbon source and complexing agent [5,10]. The composition and functional groups of the carboxylic acid have been found to influence the amount of co-deposited carbon, the morphology and the associated properties of the Fe-C coatings [2,3,5,[11][12][13][14]. In addition, the applied electrodeposition conditions, like the cathode current density, the pH value and the temperature of the electrolyte [2,3,5,15], influence the current efficiency and, hence, the chemical composition, microstructure and properties of the as-deposited coatings.…”

“…Such high amount of carbon considerably exceeds the solubility of carbon in iron at room temperature, which, typically for Fe-C alloys, suggests either the formation of iron carbides or the presence of carbon in supersaturated solid solution in the iron lattice. Previous investigations of electrodeposited Fe-C coatings by means of diffraction analysis consistently revealed the presence of one major phase in as-deposited coatings, which is interpreted either as ferrite (not containing carbon in thermodynamic equilibrium) [5][6][7]13] or as martensite (with carbon in supersaturated solid solution) [2,3,11,12,15]. The similarity of both lattices and the strong crystallographic texture of as-deposited Fe-C coatings complicate the phase analysis.…”

Hydrogen Effects on the Migration of Nanoscale Cavities in Iron

“…Cavities without hydrogen and those with hydrogen were produced by high-energy electron irradiation 14) and electro-deposition, 15) respectively.…”

“…Upon electro-deposition, high-concentration hydrogen and hydrogen-induced super-abundant vacancies are simultaneously induced into the newly deposited iron-atom layers, which yields the formation of vacancies or vacancy clusters bound with hydrogen. 15) The electro-deposition was performed using an aqueous solution of FeSO 4 , HCl, and H 3 BO 3 , at room temperature.…”

Electrodeposition of Fe-C Alloys from Citrate Baths: Structure, Mechanical Properties, and Thermal Stability

“…However, these investigations are restricted to the addition of another element of the iron group (nickel [7] or cobalt [13]) and the elements phosphorous and boron [14,15]. The codeposition of hydrogen is inherent to the electrodeposition of iron and its alloys in general [16], but was shown to be significantly enhanced in the case of Fe-C alloy deposition [17]. Since the rate of hydrogen reduction is not only enhanced during the deposition of such carbon alloys, but also when they are used as electrodes for the hydrogen evolution reaction in an alkaline medium, they are promising candidates for the commercial production of hydrogen via this route [18].…”