Rational design and controllable preparation of holey MnO2 nanosheets.

A novel technique for the design and controllable preparation of holey MnO2 nanosheets was first developed by an in situ redox reaction between the MnO2 nanosheets and adsorbed Fe2+ ions at room temperature, in which Fe2+ ions originated from a redox reaction between Cu wire and Fe3+ ions. The formation of in-plane nanopores on the MnO2 nanosheets obviously improved the rate capability when they were used as promising supercapacitor electrodes.