Designing tunable microstructures of Mn 3O 4 nanoparticles by using surfactant-assisted dispersion

Abstract

Porous Mn 3O 4 nanoparticles with tunable microstructures are synthesized from Mn(AcO) 2·4H 2O with Pluronic F127 as a dispersant. The amount of copolymer served as the surfactant in the precursor solution is varied to change/tune the specific surface area/porosity of Mn 3O 4. The textural and electrochemical properties of porous Mn 3O 4 nanoparticle are systematically characterized by means of the N 2 adsorption/desorption isotherms, scanning electron microscopic (SEM), transmission electron microscopic (TEM), X-ray diffraction (XRD), and voltammetric analyses. The interactions between manganese precursor and triblock copolymer can be used to control the microstructures of resultant oxides. Mn 3O 4 nanoparticles with tunable porosity and high surface area achieve the excellent capacitive performances (e.g., high-power characteristics and impressive capacitance retention) for next generation supercapacitors. The specific surface area indicating the electrochemically active sites for charge storage/delivery as well as the pore structure indexed by the BJH pore volume, which affects the ion transportation and electrolyte permeation, have been demonstrated to be the key factors determining the capacitive performances of Mn 3O 4 in the low-rate and high-rate processes, respectively. © 2012 Elsevier B.V. All rights reserved.