Synthesis and Characterization of Copper, Zinc, and Nickel Oxides-Based Nanocomposite by Using Clitoria ternatea Flower Extract for Antioxidant Studies and Electrochemical Applications

The paper presents an eco-friendly method for synthesizing a ternary copper, zinc, and nickel oxides nanocomposite using Clitoria ternatea flower extract as the synthesis agent. The bioactive compounds in the extract act as protective agents, facilitating the formation of CNZ and eliminating the need for additional chemical reagents. The synthesized CNZ was characterized using various analytical techniques (UV–Vis, FT-IR, SEM, TEM, PXRD, EDX, and BET), and the obtained results suggest that the formation of the composite (CNZ) and confirm its crystalline nature. TEM image demonstrated that the CNZ has a spherical shape with crystallite size varying between 8 to 20 nm. The optical absorption band gap of the CNZ has been estimated to be 3.37 eV. To explore the application of CNZ in real-world application, we do both biological and electrochemical studies. In biological studies, the anti-oxidant activity of the CNZ has been examined with a series of free radicals, such as DPPH•, ABTS•+, NO•, and O2− along with the ascorbic acid (AA) and butylated hydroxy anisole (BHA), and the obtained results showed that the composite possessed substantial activity. For electrochemical applications, we employed cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS). The CNZ-based electrode exhibited pseudocapacitive behavior, with a specific capacitance of 387.7 F g−1 at 1 A g−1, demonstrating improved charge storage. The electrode retains 90% of its specific capacitance from the initial value after repeated charge–discharge processes for 2000 cycles. Ultimately, the combined electrochemical and antioxidant performance makes CNZ nanoparticles derived from C. ternatea flower extract a promising subject for further research.