Research progress on iron oxide-based magnetic materials: Synthesis techniques and photocatalytic applications

Heterogeneous photocatalysis is a promising strategy for advanced oxidation environmental remediation. Herein, this review aims to highlight recent development in the preparation of iron oxide-based magnetic nanoparticles and their applications for photocatalytic removal of organic pollutants in aqueous solution. The usage of iron oxide-based magnetic photocatalysts has received considerable attention in recent years due to their unique properties such as excellent magnetic properties, high stability against corrosion, large surface area and high surface modification flexibility. The synthesis routes for iron oxide nanomaterials such as co-precipitation, thermal decomposition, solvothermal, hydrothermal and microelmulsion processes had been summarized. Recent advances on the surface modification of iron oxide incorporating impurity doping, metal-loading, composite semiconductors and encapsulation of iron oxide are reviewed. In addition, the effect of surface modified iron oxide-based materials on the photocatalytic degradation performance and photocatalytic reaction mechanism are discussed in detail. Lastly, the toxicological effects owing to the iron oxide-based magnetic nanoparticles and potential challenges on their application in a sustainable way are also discussed.