Synthesis of ZnFe2O4 nanoparticles with high specific surface area for high-performance supercapacitor

The specific surface area is an important parameter influencing the storage capability of materials due to its direct effect on the reaction sites availability. In this study, ZnFe 2 O 4 nanoparticles with a high specific surface area, 78.9 m 2 g −1 , were prepared by a weak ultrasonic irradiation technique. Fe(NO 3 ) 3 ·9H 2 O, Zn(NO 3 ) 2 ·6H 2 O and glucose were used as reagents and the prepared precursor was calcined in the air at 400 °C for 3 h. The product was characterized by thermogravimetric analysis, Fourier transform infrared, Raman spectra, X-ray diffraction, Brunauer–Emmett–Teller, Scanning electron microscopy as well as Transmission electron microscopy. The charge storage ability, cycling stability, and ion transport of the produced ZnFe 2 O 4 nanoparticles were examined by cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy tests in 1, 3 and 6 M KOH solutions. The highest specific capacitance of the ZnFe 2 O 4 nanoparticles was obtained 712 F g −1 at the scan rate of 2 mV s −1 in 6 M KOH electrolyte, and the capacity retention for ZnFe 2 O 4 nanoparticles was still maintained after 2000 cycles at 92.4, 94.2 and 96.6% in 1, 3 and 6 M KOH electrolytes, respectively.