Microwave-Assisted Morphology Evolution of Fe-Based Metal–Organic Frameworks and Their Derived Fe2O3Nanostructures for Li-Ion Storage

The metal–organic-framework (MOF) approach is demonstrated as an effective strategy for the morphology evolution control of MIL-53(Fe) with assistance of microwave irradiation. Owing to the homogeneous nucleation offered by microwave irradiation and confined porosity and skeleton by MOF templates, various porous Fe2O3nanostructures including spindle, concave octahedron, solid octahedron, yolk–shell octahedron, and nanorod with porosity control are derived by simply adjusting the irradiation time. The formation mechanism for the MOF precursors and their derived iron oxides with morphology control is investigated. The main product of the mesoporous yolk–shell octahedron-in-octahedron Fe2O3nanostructure is also found to be a promising anode material for lithium-ion batteries due to its excellent Li-storage performance. It can deliver a reversible larger-than-theoretical capacity of 1176 mAh g–1after 200 cycles at 100 mA g–1and good high-rate performance (744 mAh g–1after 500 cycles at 1 A g–1).