Facile controlled synthesis and growth mechanisms of flower-like and tubular MnO2 nanostructures by microwave-assisted hydrothermal method

► MnO2 nanostructures were synthesized by a microwave-assisted hydrothermal method. ► Crystal phase and morphology can be controlled by adjusting reaction temperature. ► The formation mechanism of MnO2 nanotubes follows an “oriented attachment” process.