Enhanced supercapacitive performances of hierarchical porous nanostructure assembled from ultrathin Mn[O.sub.2] nanoflakes

• Published in: Journal of materials science 2013-01, Vol.48 (2), p.714
• Main Authors: Dubal, D.P, Holze, R, Kulal, P.M
• Format: Article
• Language: English
• Subjects: Analysis; Capacitors; Chemical tests and reagents; Electrochemistry; Hydrochloric acid
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-012-6783-6

Ultrathin mesoporous nanoflakes of α-Mn[O.sub.2] films were easily prepared by mixing potassium permanganate (KMn[O.sub.4]) with hydrochloric acid in an aqueous solution. The obtained α-Mn[O.sub.2] has a tunnel structure composed of an edge-shared network of [Mn[O.sub.6]] octahedra. Scanning electron micrograph observations revealed that the obtained Mn[O.sub.2] materials have 2D frameworks which consisted of highly porous interconnected nanoflakes. TEM image shows that the ultrathin nanoflakes almost have the thickness about 3-5 nm. Nitrogen desorption analyses showed that these ultrathin Mn[O.sub.2] nanoflakes exhibited large surface area up to [10.sup.2] [m.sup.2] [g.sup.-1]. The electrochemical performances of the synthesized α-Mn[O.sub.2] ultrathin nanoflakes as supercapacitor electrode materials were studied by cyclic voltammetry cycling in 1 M [Na.sub.2]S[O.sub.4] solution. The result showed that mesoporous Mn[O.sub.2] with 2D frameworks exhibit a high capacitance of 328 [Fg.sub.-1] with 84 % stability for 1000 cycles. Thus, the obtained ultrathin α-Mn[O.sub.2] nanoflakes are suitable for its use as supercapacitor electrode materials.