Photocatalytic Performance of Spinel Ferrites and their Carbon-Based Composites for Environmental Pollutant Degradation

Spinel ferrites are magnetic materials that possess excellent magnetic properties, high surface area, high chemical stability, and tuneable characteristics, making them ideal for water purification. Owing to their multifunctionality and magnetic separation capability, these materials offer high adsorption efficiencies and rapid kinetics for removing pollutants such as metal ions, dyes, and pharmaceuticals. Additionally, spinel ferrites and their nanocomposites, particularly those combined with carbon materials, show strong photocatalytic activity in degrading contaminants. These materials generate active radicals under visible and UV light, offering a low-cost, efficient solution for water treatment. While promising, further studies are needed to advance their practical application in water treatment plants. Despite their potential, a complete understanding of the degradation mechanisms and adsorption processes concerning emerging pollutants such as dyes, pharmaceuticals and microplastics, remains incomplete. This review critically examines factors influencing the performance of spinel ferrites, including particle size, shape, substitution, and functionalization, to provide insights into their molecular-level interactions with pollutants. It analyses how synthesis methods and material modifications, such as carbon coatings and substitutions, enhance photocatalytic degradation efficiency. Additionally, the review addresses magnetic separation techniques, durability over multiple cycles, and regeneration and reusability capabilities. By consolidating current knowledge and identifying research gaps, this comprehensive analysis aims to guide the future development of spinel ferrite-based purification technologies.