Sivasankara Rao , E. and Ananthakumar, R. and Anantharaj, S. and Nithiyanantham, U. and Kundu, S. (2014) Enhanced catalytic and supercapacitor activities of DNA encapsulated b-MnO2 nanomaterials. Physical Chemistry Chemical Physics, 16. pp. 21846-21859. ISSN 1463-9076

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Abstract

A new approach is developed for the aqueous phase formation of flake-like and wire-like b-MnO2 nanomaterials on a DNA scaffold at room temperature (RT) within a shorter time scale. The b-MnO2 nanomaterials having a band gap energy B3.54 eV are synthesized by the reaction of Mn(II) salt with NaOH in the presence of DNA under continuous stirring. The eventual diameter of the MnO2 particles in the wire-like and flake-like morphology and their nominal length can be tuned by changing the DNA to Mn(II) salt molar ratio and by controlling other reaction parameters. The synthesized b-MnO2 nanomaterials exhibit pronounced catalytic activity in organic catalysis reaction for the spontaneous polymerization of aniline hydrochloride to emeraldine salt (polyaniline) at RT and act as a suitable electrode material in electrochemical supercapacitor applications. From the electrochemical experiment, it was observed that the b-MnO2 nanomaterials showed different specific capacitance (Cs) values for the flake-like and wire-like structures. The Cs value of 112 F g�1 at 5 mV s�1 was observed for the flake-like structure, which is higher compared to that of the wire-like structure. The flake-like MnO2 nanostructure exhibited an excellent long-term stability, retaining 81% of initial capacitance even after 4000 cycles, whereas for the wire-like MnO2 nanostructure, capacitance decreased and the retention value was only 70% over 4000 cycles. In the future, the present approach can be extended for the formation of other oxide-based materials using DNA as a promising scaffold for different applications such as homogeneous and heterogeneous organic catalysis reactions, Li-ion battery materials or for the fabrication of other high performance energy storage devices

Item Type:	Article
Uncontrolled Keywords:	Super capacitors; nanomaterials
Subjects:	Nanotechnology Electrochemical Materials Science
Divisions:	UNSPECIFIED
Depositing User:	Dr. N Meyyappan
Date Deposited:	06 Jan 2015 11:36
Last Modified:	06 Jan 2015 11:36
URI:	http://cecri.csircentral.net/id/eprint/3128

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