Liquid‐Phase Synthesis of Iron Oxide Nanostructured Materials and Their Applications

Owing to their high natural abundance, low cost, easy availability, and excellent magnetic properties, considerable interest has been devoted to the synthesis and applications of iron oxide nanostructured materials. Liquid‐phase synthesis methods are economical and environmentally friendly with low energy consumption and volatile emissions, and as such have received much attention for the preparation of iron oxide nanostructured materials. Herein, the liquid‐phase synthesis methods of iron oxide nanostructured materials including the co‐precipitation method, microemulsion method, conventional hydrothermal and solvothermal methods, microwave‐assisted heating method, sonolysis method, and other methods are summarized and reviewed. Many iron oxide nanostructured materials, self‐assembled nanostructures, and nanocomposites have been successfully prepared, which are of great significance to enhance their structure‐dependent properties and applications. The specific roles of liquid‐phase chemical reaction parameters in regulating the chemical composition, structure, crystallinity, morphology, particle size, and dispersive behavior of the as‐prepared iron oxide nanostructured materials are emphasized. The biomedical, environmental, and electrochemical energy storage applications of iron oxide nanostructured materials are discussed. Finally, challenges and perspectives are proposed for future investigations on the liquid‐phase synthesis and applications of iron oxide nanostructured materials.