SYNTHESIS OF COBALT AND COPPER NANOFERRITES BY A SOL-GEL METHODUSING PLANTS AND THEIR CATALYTIC ACTIVITY

Abstract. This brief review presents an analysis of data from the past five years on the “green” synthesis and catalytic activity of cobalt and copper nanoferrites, which are characterized by a wide range of applications. Due to their large reserves, availability, and abundance, plants are the best bioagents for the sol-gel synthesis of ferrites, which utilizes plant extracts along with precursors. Extracts can be obtained from leaves, fruits, roots, seeds, and flowers of plants, which contain polysaccharides, carbohydrates, phenols, flavonoids, terpenoids, and amino acids, which can act as chelating, reducing, and stabilizing agents for ferrite nanoparticles. Existing literature reviews examine the synthesis and application of green nanoferrites for water purification, heavy metal removal, their antibacterial activity, photocatalytic activity in the degradation of various dyes, and their potential use in biological processes. In contrast, this brief review focuses on a comparative analysis of methods for obtaining extracts from various plants, as well as the processing conditions of precursor and extract mixtures for ferrite synthesis. The influence of extract concentration and heat treatment method on the properties of the synthesized ferrites and nanoparticle size is examined. Examples of the few catalytic reactions involving nanoferrites synthesized by the sol-gel method using plant extracts are provided. The development of new nanoferrite-based catalysts using green chemistry methods, using plants, is a promising direction for the synthesis of various catalytic systems, both from an environmental and economic perspective.