Facile solvothermal synthesis of porous ZnFe2O4 microspheres for capacitive pseudocapacitors

A facile and cost-effective solvothermal approach to the fabrication of ZnFe2O4 microspheres composed of nanocrystals has been developed. The morphology and structure of the products were characterized by X-ray powder diffraction, transmission electron microscopy, and field-emission scanning electronic microscopy, and N2-adsorption–desorption. Meanwhile, the magnetic properties of the product were investigated via vibrating sample magnetism. Finally, the electrochemical performance of the obtained ZnFe2O4 microspheres was measured by cyclic voltammetry and galvanostatic charge–discharge techniques. The results show that such structured ZnFe2O4 has a specific capacitance of 131 F g−1 and stable cycling performance with 92% capacitance retention after 1000 cycles, which make it have a potential application as a supercapacitor electrode material.