Metal Organic Frameworks-Templated Hollow Mn<sub>2</sub>NiO<sub>4 </sub>Flower for Enhanced Supercapacitor Electrodes

A facile strategy of uniform flower-shaped binary-metal-based metal-organic frameworks (MOFs) has been successfully synthesized via a simple hydrothermal method as the precursor of porous Mn 2 NiO 4 nanostructures. After heat treatment at different temperatures, the as-prepared Mn 2 NiO 4 inherits the morphologies of MOFs and can hold until 450°C. This porous Mn 2 NiO 4 , used as supercapacitor electrodes, exhibits a high specific capacitance (531.5 F g - 1 at a current density of 1.0 A g -1 ), with a relatively high specific surface area (114.2 m 2 g -1 ). The high capacitance is mainly attributed to the porous and hierarchical structure, which facilitates fast diffusion of active ions, improves structural stability and large contact area between Mn 2 NiO 4 and the electrolyte. The developed synthetic strategy may provide design guidelines for constructing advanced ternary nanostructured supercapacitors electrode.