Nanocomposites and nanomaterials

Nanostructured multilayer metal hydroxide coatings 
as cathode and anode materials
Maizelis A.A.
Department of Technical Electrochemistry, National Technical University «Kharkiv Polytechnic Institute», Kyrpychova str., 2, Kharkiv-61002, Ukraine. 
E-mail: a.maizelis@gmail.com
Electrosynthesis of various compounds requires electrodes, the most important characteristics of which are catalytic activity in the target electrode reaction, performance, corrosion resistance in the medium used, stability during operation, etc. These characteristics can be significantly improved when using nanomaterials. At the same time, the operation of electrodes in industry also assumes attention to their cost and ease of manufacture.
Nickel-containing electrode materials are relatively cheap. Nickel and its alloys are known for a long time. Last years a number of nanostructured materials have been proposed, e.g. nickel-containing substrates with high-developed surface, and coatings based on it.
Such materials include multilayer metal-hydroxide coatings consisting of layers of metals, alloys and layers containing a mixture of metals with their hydroxides [1,2]. Various options have been proposed for their subsequent treatment to obtain both cathode and anode nanostructured materials:
 (a) electrochemical reduction of the surface for the use in cathodic reactions (nickel-copper and zinc-nickel-copper multilayer electrodes for hydrogen evolution);
 (b) electrochemical oxidation to produce oxohydroxides (multilayer nickel-copper electrode for electrochemical oxidation of low-molecular alcohols and polysaccharides);
 (c) electrochemical oxidation to produce oxides (multilayer SnO2-SbxOy electrode for the electrochemical destruction of organic compounds).
The proposed electrodes with multilayer coatings have characteristics comparable to the more expensive nanostructured electrodes having more complex production process.

1.	Maizelis A., Bairachniy, B. Electrochemical formation of multilayer metal and metal oxide coatings in complex electrolytes. In international conference on nanotechnology and nanomaterials. 2017. P. 557-572. 
2.	Maizelis, A. Multilayer Nickel–Copper Anode for Direct Glucose Fuel Cell. J. Electrochem. En. Conv. Stor. 2019. 16(4), P. 041003.