Tween modified CuFe2O4 nanoparticles with enhanced supercapacitor performance

Binary metal oxides CuFe 2 O 4 can be a low-cost and high-performance pseudo-capacitive electrode material. However, their large size distributions and low dispersion caused by agglomeration can not exert their potential capacity. Hence, we used tween to modify CuFe 2 O 4 (CuFe 2 O 4 -T) nanoparticles via a facile hydrothermal method. The composite nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, UV-Vis reflectance spectroscopy, and Fourier transform infrared spectroscopy. After modification, CuFe 2 O 4 -T showed high purity, greatly reduced particle size with the diameter about 10–20 nm, and decreased bandgap energy. When serving as supercapacitor electrodes, their electrochemical behaviors were examined by cyclic voltammetry, galvanostatic charge-discharge study, and electrochemical impedance spectroscopy. CuFe 2 O 4 -T exhibited improved supercapacitor behavior, with a specific capacitance of 437.3 F g −1 at the scan rate of 0.004 V s −1 in 0.5 M H 2 SO 4 electrolyte, 88.6% capacitance stability retention over 2000 cycles. An asymmetric supercapacitor device was assembled by using CuFe 2 O 4 -T as a positive electrode, which showed good capacitive behavior and cyclic stability. This work indicates that tween can effectively improve the performance of CuFe 2 O 4 nanoparticles, and CuFe 2 O 4 -T will have great promise for wide electrochemical application.