Authors: D. G. Muratov | Л. В. Кожитов | И. В. Запороцкова | А. В. Попкова | В. В. Слепцов | А. В. Зорин
Source: Izvestiya Vysshikh Uchebnykh Zavedenii Materialy Elektronnoi Tekhniki = Materials of Electronics Engineering (article, 2024-01-12)
Field: Chemistry — Inorganic Chemistry

Metal-organic frame structures and composites based on them: structural features, synthesis methods, electrochemical properties and prospects (review) This paper presents an overview of various types of organometallic frameworks (MOFs), their structural features, and classification. The main methods and approaches to the synthesis of both MOFs and composite materials based on them are also considered.The structure of MOFs is a regular three-dimensional lattice formed by organic linkers and metal clusters. The nature of interconnections and types of metals can significantly affect the spatial structure and size of MOF crystals. MOFs can be nano-, micro-, and meso-sized, dense and porous, bulk and layered. This all determines their wide range of properties and applications.Particular attention is paid to the prospects and ways to control and manipulate the shape of crystals, their size, and the spatial relationships between organic components with metal ions.This review focuses on zeolite-like frameworks (ZIFs) as the most interesting in terms of structure, synthesis, and applications in the field of materials for electrochemical current sources. Possibilities of modification and control of properties of these ZIFs and composite materials based on them by means of composition control, creation of porous structures, and introduction of impurities, including those with magnetic properties, are considered. Various variants of synthesis of complex composite materials by controlled pyrolysis of MOFs as a simple and scalable process are considered. The influence of heat treatment conditions on the final properties is demonstrated, as well as the prospects for the use of such materials in electrochemistry applications.As one of the options for changing the properties of MOFs and composite materials based on them, an approach based on doping of MOFs with ZIF-67 structure with another metal is presented. In particular, the scientific team of the authors realized the synthesis of cobalt MOFs in which Co is partially substituted by manganese at the synthesis stage. In addition, a simple technique of synthesis by coprecipitation in aqueous solution was used, but modified by ultrasonic action, which shortens the synthesis time. Electrochemical studies showed that the specific electrochemical capacitance of electrodes made of pyrolyzed MOFs with partial substitution of cobalt for manganese is significantly higher than that of materials without manganese. Both specific capacitance and energy density increase with increasing manganese content in MOF. Mn doping of MOF allows to significantly improve (from 100 to 298 F/g at current density of 0.25 A/g) the electrochemical characteristics of electrode materials for hybrid supercapacitors based on them. The results obtained by the authors indicate that the substitution of cobalt with manganese is an effective way to improve the electrochemical characteristics of MOFs.Thus, the article demonstrates by the example of literature review and practical experiment that the development of new approaches to the design of composite materials based on MOFs, as well as the study of physical and chemical regularities of interaction of these materials with various kinds of carriers is a very urgent task. Electrochemistry ; Materials science ; Frame (networking) ; Metal ; Composite material ; Metallurgy ; Mechanical engineering ; Engineering ; Chemistry ; Electrode Metal-Organic Frameworks: Synthesis and Applications ; Polyoxometalates: Synthesis and Applications ; Conducting polymers and applications