Magnetic-field-assisted hydrothermal synthesis of 2 × 2 tunnels of MnO2 nanostructures with enhanced supercapacitor performance

An effective magnetic-field-assisted hydrothermal synthesis was used to induce the growth of 2 × 2 tunnel MnO2 nanostructures for supercapacitor application. The as-fabricated electrode from the MnO2 nanostructures exhibited an enhanced specific capacitance of 306 F g−1 at 0.5 A g−1 and desirable cyclic stability, which considerably exceed the performance of MnO2 material prepared with and without a high magnetic field, making it a promising electrode material for supercapacitors.