The mechanism, protective properties, microstructure, phase composition of coats on steel have been investigated. According to the developed method, the coats were deposited potentiodynamically and potentiostatically in an aqueous solution of sodium tripolyphosphate. Based on the results of electrochemical studies, it has been established, that on potentiodynamic curves, characterizing the corrosion behavior of low-carbon steel in an aqueous sodium TPP solution, up to three passivation plateaus can be observed. The multi-stage formation mechanism of tripolyphosphate coat has been proposed. The mechanism includes three stages: at the start the adsorptive film is formed, that afterwards is modified two times, accompanied by a change of properties and composition. By using the methods of optical and scanning electron microscopy, X-ray diffraction, it has been established that the coat formed in an aqueous Na TPP solution by the potentiodynamic method under conditions of complete passivation, is composed of two layers: first – thin, compact layer, that contains a crystalline phase of phosphate nature, and second – thick hydrophilic layer, capable of drying. Such coat possesses the best protective properties in 0.1 N Na₂SO₄ solution, that models conditions of atmospheric corrosion. The nature of the electrochemical formation mechanism of tripolyphosphate coats and features of their structural and phase composition have been established. The further studies will be directed at the development of effective deposition methods of tripolyphosphate coats with estimated set of properties for the protection of metal goods from atmospheric and high-temperature gas corrosion.

In this paper, we present a method developed for soft electrochemical etching of fluorine-doped tin oxide-coated glass (FTO-coated glass) that consists of FTO treatment with alternating polarity current in a simple electrolyte. The developed method was found to alter morphology and hydrophilicity of FTO. In order to study the influence of soft electrochemical etching on FTO functionally as a substrate for electrochromic films, a Ni(OH)₂-based electrochromic film was deposited onto treated FTO. It was discovered that films deposited onto etched substrate had significantly improved uniformity and higher coloration degree than films deposited on untreated FTO.

Nickel hydroxide is widely used as an active material for hybrid supercapacitors. To improve the characteristics of supercapacitors, Ni(OH)₂ with the optimal parameters to be determined should be synthesized. For this, Ni(OH)₂ samples were prepared by various methods: decomposition, homogeneous precipitation, electrochemical synthesis using slit diaphragm electrolyzer under various current densities, with diaphragm or membrane, carbonate activation, immediate ultrasound post­treatment and an industrial sample, prepared by chemical route. Structural properties of the samples were studied by X­ray phase analysis, specific surface area – BET method by nitrogen adsorption, electrochemical characteristics – galvanostatic charge­discharge cycling in the supercapacitor mode. It has been demonstrated that high specific capacity is the most affected by α (or layered α+β) structure, optimal (average or low) crystallinity, introduction of activating additive and the ability of particle agglomerates to undergo breakdown into smaller particles during charge­discharge. Specific surface area has little influence on specific capacity. The sample prepared in slit diaphragm electrolyzer at 15.7 A/dm² has a layered type of crystal structure, and the ability of particle agglomerates to undergo breakdown into smaller particles during charge­discharge, and showed the highest specific capacity of 650 F/g.