Investigation of oxidation-reduction processes of nickel hydroxide precipitation and their carbothermical reduction

• Published in: Physical chemistry chemical physics : PCCP 2024-12, Vol.26 (47), p.29364-2937
• Main Authors: Bohatyrenko, Viktoriia, Kamenskyh, Dmytro, Jafarov, Maarif, Tkachenko, Tetiana, Yevdokymenko, Vitalii
• Format: Article
• Language: English
• Subjects: Aqueous solutions; Corrosion cell; Depolarization; Deposition; Electrolytic cells; Hydroxides; Magnesium; Magnetic properties; Microparticles; Nickel compounds; Oxidation; Phase composition; Reducing agents; Task complexity
• ISSN: 1463-9076; 1463-9084; 1463-9084
• DOI: 10.1039/d4cp03077j

Most of the known methods for the chemical production of nickel nano- and microparticles, nickel oxides and hydroxides use various reducing agents and solvents, which are often toxic to the environment. As a rule, these methods are energy-consuming, lengthy and multi-stage, requiring complex equipment. Therefore, the development of a simple and "green" process for the synthesis of nickel-containing particles, including those with magnetic properties, remains one of the priority tasks. In this paper, a new physicochemical method for oxidation-reduction contact deposition of nickel( ii ) hydroxide nano-microparticles on the surface of magnesium particles from aqueous solutions of nickel-containing electrolyte is proposed. This method is based on the local corrosion of microgalvanic cells' formation with predominant hydrogen depolarization. The proposed method was used to obtain nickel( ii ) hydroxide samples and study their morphology using SEM, as well as their phase composition using XRD analysis. It has been proven that the shape and structure of the resulting Ni(OH) 2 particles depend on the contact deposition conditions: depending on the surface state of the magnesium particles as a reducing agent, it is possible to obtain both plate-shaped α/β-Ni(OH) 2 particles and three-dimensional β-Ni(OH) 2 "flowers" with different degrees of crystallinity. Most of the known methods for the chemical production of nickel nano- and microparticles, nickel oxides and hydroxides use various reducing agents and solvents, which are often toxic to the environment.