Electrochemical performance of CuBi2O4 nanoparticles synthesized via a polyacrylamide gel route

CuBi2O4 nanoparticles were prepared via a polyacrylamide gel route. Field-emission scanning electron microscopy observation shows that the particles are shaped like spheres and have an average particle size of similar to 230 nm. Ultraviolet- visible diffuse reflectance spectroscopy reveals that the particles have a bandgap energy of 1.88 eV. The electrochemical performance of the sample was investigated by means of cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy in 2 M KOH, 6 M KOH, and 2 M NaOH electrolytes at different temperatures. It is demonstrated that the temperature has an important effect on the electrochemical performance of the sample, and relatively higher specific capacitance is observed at 45 degrees C, reaching 1 458 F g(-1) in 2 M KOH electrolyte at a current density of 2 A g(-1). In addition, the sample exhibits an increased capacitance in a higher-concentration electrolyte, but its charge-discharge cycling stability is decreased. Moreover, it is found that the sample exhibits relatively larger specific capacitance in KOH electrolyte than in NaOH electrolyte.