The 1D low-crystalline and ultrathin MnO2-RT nanotubes consisted of tiny nanoflakes are rapid synthesized at ambient temperature through a facile oxidation-etching method, where Cu nanowires are served as sacrificial templates. Meanwhile, the MnO2-RT nanotubes can be undergone further nucleation and growth to generate 3D porous MnO2 nanotubes by calcination treatment and hydrothermal reaction, respectively. Importantly, the high specific capacitance of 384.6 F g(-1), is obtained at the current density of 0.25 A g(-1) for the low-crystalline MnO2-RT nanotubes, owing to its ultra-thin wall thickness, high surface area and highly disordered structure. Furthermore, the cycle stability of the low-crystalline MnO2 nanotubes can be improved by hydrothermal treatment, owing to the enhanced crystallinity. (C) 2019 Elsevier Inc. All rights reserved.