Effect of the fuel on the partial stabilization of nickel barium oxide electrocatalyst for supercapacitor applications

The solution combustion method is a cost-effective, straightforward, and attractive method for the fabrication of the electrocatalyst. In this work, we fabricated nickel barium oxide electrocatalyst with solution combustion method with four different fuels such as thioacetamide (NB1), citric acid (NB2), urea (NB3), and glucose (NB4) respectively. Working electrodes were fabricated by drop casting the synthesized electrocatalyst dispersed in ethanol onto porous carbon paper. Cyclic Voltammetry (CV) analysis of each sample was done at 5 mV/s and a potential range of 0–0.55 V which compares the cyclic voltammogram of the samples. The scanning electron micrographs confirm the presence of aggregated nanosized particles of around 124.1 ± 1.7 nm. The electrocatalyst prepared using urea as the fuel showed the highest charge storage capacity. The two amine groups of urea partially stabilize the nickel and barium from the electrocatalyst. This effect transfers the slight positive charge on nickel as well as on barium, which enhances the charge transfer reaction resulting in the enhancement of charge holding capacity of nickel barium oxide. The electrochemical impedance analysis further supports the above findings by showing the minimum charge transfer resistance and highest pseudo-capacitance. Thus, the partial stabilization of the electrocatalyst species can enhance the charge storage capacity. Such an electrocatalyst can find potential applications in energy storage devices like supercapacitors.