Facile Preparation of Mno 2 Nanorods and Evaluation of Their Supercapacitive Characteristics Publisher



Aghazadeh M¹ ; Asadi M² ; Maragheh MG¹ ; Ganjali MR^{3, 4} ; Norouzi P³ ; Faridbod F³ Show Affiliations
Source: Applied Surface Science Published:2016

Abstract

The first time pulsed base (OH - ) electrogeneration to the cathodic electrodeposition of MnO 2 in nitrate bath was applied and MnO 2 nanorods were obtained. The deposition experiments were performed under a pulse current mode with typical on-times and off-times (t on = 10 ms and t off = 50 ms) and a peak current density of 2 mA cm -2 (I a = 2 mA cm -2 ). The structural characterization with XRD and FTIR revealed that the prepared MnO 2 is composed of both α and γ phases. Morphological evaluations through SEM and TEM revealed that the prepared MnO 2 contains nanorods of relative uniform structures (with an average diameter of 50 nm). The electrochemical measurements through cyclic voltammetry and charge-discharge techniques revealed that the prepared MnO 2 nanostructures reveal an excellent capacitive behavior with specific capacitance values of 242, 167 and 98 F g -1 under the applied current densities of 2, 5 and 10 A g -1 , respectively. Also, excellent long-term cycling stabilities of 94.8%, 89.1%, and 76.5% were observed after 1000 charge-discharge cycles at the current densities of 2, 5 and 10 A g -1 . © 2015 Elsevier B.V. All rights reserved.