A new bilayer nanostructure of manganese oxide is developed by two-step hydrothermal reactions. Much higher mass loading of manganese oxide is successfully maintained (similar to 2.4 mg cm(-2)) through this new type of nanoarchitecture. In the meanwhile, the desired high specific surface area, good conductivity and ion accessibility are obtained, therefore giving rise to significantly improved electrochemical performance for manganese oxide (e.g., specific capacitance of 559.5 F g(-1) and excellent cycle ability). By growing the second layer of MnOx on the Ni foam current collector that is pre-covered by a MnO2 substrate layer, uniformly thin and continuous nanosheets from the second layer MnOx with excellent surface coverage and open mesoporous structure are obtained, leading to large surface area and fast charge transfer. This novel architecting explores the new potential of manganese oxides as high performance supercapacitor electrodes. (C) 2015 Elsevier B.V. All rights reserved.