Hydrothermal preparation of octadecahedron Fe3O4 thin film for use in an electrochemical supercapacitor

A Fe3O4 film with regularly edge-affected cubic (octadecahedron) morphology was successfully prepared on stainless steel foil by a simple and benign hydrothermal process. The potential for the use of the film in a supercapacitor was tested by investigating the electrochemical behavior of the Fe3O4 film using cyclic voltammetry (CV) and galvanostatic charge/discharge tests. The Fe3O4 film showed a CV indicative of a typical pseudocapactive behavior in 1 mol L−1 Na2SO3 solution. Furthermore, this film exhibited a specific capacitance of 118.2 F g−1 at the current of 6 mA between −1 and 0.1 V with a capacity retention of 88.75% after 500 cycles.