Utilization of Banana Juice Biomass Waste to Activate CuO/NiO Composites for Electrocatalytic Oxidation of Urea in Alkaline Media

The hydrothermal synthesis of CuO/NiO composites was conducted using banana fruit biomass waste. In this study, X-ray powder diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy were used to investigate the crystalline properties, shape structure, and functional group characterization of CuO/NiO composites. The typical morphology of the prepared materials consisted of irregular nanoparticles arranged into clusters of less than 200 nanometers in size. In spite of this, the CuO/NiO composites showed monoclinic CuO and cubic NiO phases and were therefore successfully synthesized. It was observed that rotten banana fruit juice had a significant impact on the particle size and crystal quality of CuO/NiO composites. This was due to the presence of capping, reducing, and stabilizing agents in banana fruit juice. Under alkaline conditions, the CuO/NiO composites were found to be highly electro catalytically active toward the oxidation of urea. Sample 2, which was prepared by adding 1.2 g of CuO decorated with NiO, showed a linear increase in urea detection ranging from 0.1 mM to 17 mM, with a limit of detection of 0.004 mM. Furthermore, sample 2 of the CuO/NiO composite demonstrated exceptional stability, selectivity, and reproducibility. Consequently, sample 2 of CuO/NiO could effectively detect urea in spinach, lotus root, milk, and curd. The improved performance of sample 2 of the CuO/NiO composite can be attributed to its favorable surface properties, which contain enriched active sites and a rapid charge transfer rate.