Controlled synthesis and characterization of layered manganese oxide nanostructures with different morphologies

Study of Poly (3,4-ethylenedioxythiophene)/MnO2 as Composite Cathode Materials for Aluminum-Air Battery

“…1(a), all the diffraction peaks associated with α-MnO 2 and β-MnO 2 phases prepared via the hydrothermal method are evidently indexed to the pure tetragonal structure (space group I4/m of α-MnO 2 and space group P42/mnm of β-MnO 2 ). In Table 1 However, tube-like or needle-like of tunnel-structured MnO 2 system was reported in some literatures, which is mainly contributed to different precursors used for the synthesis and the competition of anions and cations [14]. BET results showed that the pore size and pore volume of prepared α-MnO 2 (69.2 nm and 0.3689 cm 3 g -1 ) were greater than that of β-MnO 2 (35.6 nm and 0.2192 cm 3 g -1 ), while the specific surface area of α-MnO 2 (22.63 m 2 g -1 ) was smaller than that of β-MnO 2 (29.96 m 2 g -1 ).…”

“…Of these, α, β, γ, δ and ε types of MnO 2 are more discussed elsewhere [5,[12][13][14][15]. As different numbers and forms of octahedrons develop a tunnel structure with joint corners, MnO 2 with different structures will be formed, and the different crystal types, sizes, shapes and other factors all will affect their optical, electrical and magnetic properties.…”

“…As different numbers and forms of octahedrons develop a tunnel structure with joint corners, MnO 2 with different structures will be formed, and the different crystal types, sizes, shapes and other factors all will affect their optical, electrical and magnetic properties. According to the studies of Liu et al [14], different precursors are likely to form the above-mentioned MnO 2 through certain temperatures and time, but the obtained MnO 2 samples may have different crystal forms or appearances. The key to determine the formation of different phases is the concentration competition of the potassium and hydrogen ions in the reaction process [14].…”

“…According to the studies of Liu et al [14], different precursors are likely to form the above-mentioned MnO 2 through certain temperatures and time, but the obtained MnO 2 samples may have different crystal forms or appearances. The key to determine the formation of different phases is the concentration competition of the potassium and hydrogen ions in the reaction process [14]. Wang et al also pointed out that the precursor concentration is likely to be the main factor determining the MnO 2 crystal forms [15].…”

Enhanced electrochemical properties of cobalt doped manganese dioxide nanowires

“…Apart from the conductivity and transport properties, the specific capacitance mainly depends upon the surface area of the materials. Various morphological structures of MnO 2 including nanorods, nanowires, nanosheets, nanoflakes, and nanoflowers [37][38][39][40] have been synthesized and effectively studied for their electrochemical performance. Mostly an hydrothermal method was adopted for the synthesis of the above mentioned MnO 2 nanostructures.…”