title: Enhanced supercapacitor performance of Mn3O4 nanocrystals by doping transition-metal ions.
abstract: Pristine and transition-metal-doped Mn3O4 nanocrystals shaped in octahedrons have been synthesized by hydrothermal reduction of potassium permanganate and characterized by SEM/TEM, X-ray diffraction, X-ray photoelectron spectroscopy, and electrochemical experiments. The results reveal that a multistep reduction process is taking place, and the introduction of doping ions causes a direct synthesis of single-phase Mn3O4 nanocrystals. To assess the properties of Mn3O4 nanocrystals for their use in supercapacitors, cyclic voltammetry and galvanostatic charging-discharging measurements are performed. The phase stability during cycling and charge-transfer behavior are greatly improved by doping with transition metal, and Cr-doped Mn3O4 nanocrystals exhibit a maximum specific capacitance of 272 F g(-1) at a current density of 0.5 A g(-1). These doped Mn3O4 nanocrystals could be a promising candidate material for high-capacity, low-cost, and environmentally friendly electrodes for supercapacitors. In addition, these results have verified the ability of doping to improve capacitive performances of spinel-structured transition-metal oxides.
authors.affiliation: School of Chemistry and Chemical Engineering, Guangxi University , Nanning 530004, P. R. China.
authors.forename: Ruiting
authors.initials: R
authors.lastname: Dong
authors.forename: Qinglan
authors.initials: Q
authors.lastname: Ye
authors.forename: Lili
authors.initials: L
authors.lastname: Kuang
authors.forename: Xu
authors.initials: X
authors.lastname: Lu
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Xue
authors.initials: X
authors.lastname: Zhang
authors.forename: Guojin
authors.initials: G
authors.lastname: Tan
authors.forename: Yanxuan
authors.initials: Y
authors.lastname: Wen
authors.forename: Fan
authors.initials: F
authors.lastname: Wang