A facile route to synthesize CuO sphere-like nanostructures for supercapacitor electrode application

The sphere-like nanostructure has been developed using the cetyl trimethyl ammonium bromide (CTAB) template-assisted simple co-precipitation method subsequently succeeded by an effective heat treatment. The surface morphological features of the CuO materials can be easily tuned using various concentrations of the CTAB template. The thermal behavior, phase and bonding characteristics were analyzed using thermogravimetric analysis (TGA), Scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD) and Fourier transform infrared spectroscopic (FTIR) analyses. The morphological study declares that the prepared CuO has aggregated definitely shaped nanoparticles and sphere-like nanostructure morphologies. The sphere-like nanostructure exhibits large reaction centers, which permits well electrolyte accessible and provide the shortest path for ions. The electrochemical performance of the materials has been studied using cyclic voltammetric (CV) and galvanostatic charge/discharge (GCD) analysis. The sphere-like CuO nanostructure delivers 494 F g⁻¹ as the specific capacitance at a scan rate of 5 mV s⁻¹ whereas the GCD curves provide the specific capacitance of 468 F g⁻¹ at a current density of 1 A g⁻¹. The retainment of 94% of the initial capacitance after 2000 cycles of CV curves at a scan rate of 100 mV s⁻¹ reveals the cyclic stability studies. The present study recommends the synthesis of low-cost CuO material and its fine-tuning surface characteristics to be very much essential for energy storage applications.