Magnetic and electrochemical properties of CuFe2O4 hollow fibers fabricated by simple electrospinning and direct annealing

Copper ferrite (CuFe2O4) hollow fibers were fabricated by direct annealing of electrospun precursor fibers with appropriate heating rate. The crystal structure, morphology, magnetic properties and electrochemical properties of as-made CuFe2O4 hollow fibers were investigated by using X-ray diffraction, Fourier-transformed infrared spectra, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometer, and electrochemical workstation. The results show that the appropriate heating rate of 0.5 degrees C min(-1) can result in the formation of hollow tetragonal structural CuFe2O4 fibers. Hollow fibers after annealing at high temperatures still retain the one-dimensional texture and the walls of hollow fibers consist of many nanoparticles. Magnetization results indicate that the CuFe2O4 hollow fibers have a ferromagnetic behavior and their specific saturation magnetization value increases with an increase in the annealing temperature. Moreover, the electrochemical results suggest that the capacitance characteristic of the CuFe2O4 hollow fibers is a typical pseudocapacitive capacitance. The value of the specific capacitance gradually decreases with the increase in the discharge current density.