Growth of nickel-oxide structures and investigation of capacitive behavior

In this study, NiO thin films were produced on graphite substrate by the electrodeposition method. All these films were grown from Ni(NO3)2 solutions with different pH values. The desired pH values were adjusted with NH3 solution and the films were produced at these pH values (4,1; 4,6; 5,1; 5,6 and 6,3). After growth, the films were annealed for 1 hour, 2 hours and 3 hours and their capacitive behaviors were examined at different pH values for different capacitive solutions (H2SO4, Na2SO4 and KOH). Among these annealing times, the highest specific capacitance (65 mF/cm2 ) value was obtained in the film annealing for 2 hours. For these different pH values, the highest specific capacitance value was found as 9.6 mF/cm2 at 4.6 pH values. Among these different capacitive solutions, the highest specific capacitance value (65 mF/cm2) was found for KOH solution. The structural analysis of the films was performed using Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) patterns. The Scanning Electron Microscopy (SEM) and surface mapping techniques were used to study morphological structures. The chemical analyses were determined by Energy Dispersive X-Ray Spectroscopy (EDX) method.