Metal organic frameworks-templated hollow Mn₂NiO₄ 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 Mn₂NiO₄ nanostructures. After heat treatment at different temperatures, the as-prepared Mn₂NiO₄ inherits the morphologies of MOFs and can hold until 450ºC. This porous Mn₂NiO₄, 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 m² 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 Mn₂NiO₄ and the electrolyte. The developed synthetic strategy may provide design guidelines for constructing advanced ternary nanostructured supercapacitors electrode.