Importance of Metal Cations and Water for Stability of MnO2 Crystals

Metal cations as well as water are important factors to control the synthesis of MnO2 crystal nanostructures. In this work, systemic Density functional theory calculations about α, β, δ-MnO2 are presented to show the importance of metal cations and water for the structure stability and energy stability of MnO2. It is shown that the α-MnO2 crystal and its (110) surface will crash without the tunnel cations such as K+, and the distance between the layers of the δ-MnO2 will be significantly lower than that of the experimental results without the interlayer metal cations and water. At the same time, α-MnO2 and δ-MnO2 can be more stable than β-MnO2 with metal cations and water, and vice versa.