Plant-Mediated Green Synthesis of Magnetic Spinel Ferrite Nanoparticles: A Sustainable Trend in Nanotechnology

Nanotechnology is very important in developing sustainable technologies for the future. Increased demand for metal and metal oxide nanoparticles has led to their large-scale production using conventional chemical methods with various toxic solvents. These techniques produce poisonous and harsh products that present a biological risk to the environment and have terrible effects on the life of microbes, plants, vertebrates, and invertebrates at different trophic levels. Thus eco-friendly "green" synthesis methods have become necessary to synthesize nanoparticles using biological entities, such as plants and microorganisms. When compared to other methods, "green" synthesis is safer for human health and the environment. Plants, the main factory for the green synthesis of nanoparticles, have been used extensively for this purpose. This review, focuses on eco-friendly synthesis to design spinel ferrite nanoparticles, particularly, using extracts from plant products that act not only as precursors but also as reductants and stabilizers during the synthesis process. The outstanding features of these nanoparticles allows for their promising applications in catalysis, lithium-ion batteries, information storage, magnetic cores, ferrofluids, microwave, and medicine. This important review also highlights noteworthy recent developments related to the green synthesis of plant-mediated magnetic spinel nanoparticles and their fundamental applications.