Mesoporous-assembled MnO2 with large specific surface area

Abstract

Mesoporous-assembled MnO₂ with large specific surface area was prepared by heating a delaminated MnO₂ nanosheet slurry with NH₄HSO₄ at 175 °C. When the molar ratio of NH₄HSO₄ to MnO₂ is 2.1, the obtained material had the largest specific surface area of 456 m² g⁻¹, which gives a high specific capacitance of 281 F g⁻¹ at a current density of 0.25 A g⁻¹ and excellent cycling performance with about 1.9% loss after 2000 cycles.