Mild hydrothermal synthesis of γ-MnO₂ nanostructures and their phase transformation to α-MnO₂ nanowires

Abstract

Abstract

Synthesis and Characterization Nano Structure of MnO2 via Chemical Method

“…It is well known that MnO2 has various polymorphs (i.e. exist in various crystal structure) -, -, -, -, -and -types and so forth, each form differs from the other in the arrangement of the basic structural unit of ([MnO6] octahedron).According to these links of octahedron, MnO2 may exist as tunnel structure similar to chain such as -, -, and -types, layered or sheet structure like -MnO2, and as 3D structure like -type [21]. -MnO2, -MnO2 and -MnO2 phases have onedimensional (1D) tunnels with X*X octahedral cross section (X= 5 1, 2, 3, or 4) in their crystal structure, the phase -MnO2 is 2D-layered compound, while -MnO2 has 3D spinel structure [21].…”

Improvement of the electrochemical performance of nanosized α-MnO2 used as cathode material for Li-batteries by Sn-doping

“…It has been pointed out by several workers that the particle morphology is strongly dependent on the synthetic conditions. For instance, the direct reaction of potassium permanganate with fumaric acid via a mild hydrothermal route favors the growth of ␣-MnO 2 nanowires or nanorods [21][22][23][24]. Portehault et al have shown that the monocrystalline primary nanorods are well ordered together at low pH on the mesocrystal [23].…”

Green synthesized AgNPs from Periploca hydaspidis Falc. and its biological activities

“…The Purified nanoparticles exhibited absorption peaks at 1,222 cm −1 , 1,375 cm −1 , 1,552 cm −1 , 2,916 cm −1 , 3,420 cm −1 due to cyclic OCH 3 , C=O, C–OOH, CH 2 , and OH functional groups, respectively. The additional absorption peak at 2,314 cm −1 is due to CO 2 absorption band (Khan, Durrani, Mehmood, & Khan, 2011). The absorption band at 1,375 cm −1 and 1,552 cm −1 assign the asymmetric vibration of carboxylate group on the surface of AgNPs (Manna, Kulkarni, Bandyopadhyay, & Vijayamohanan, 1997).…”