Benign-by-design plant extract-mediated preparation of copper oxide nanoparticles for environmentally related applications

A facile, cost-competitive, scalable and novel synthetic approach is used to prepare copper oxide (CuO) nanoparticles (NPs) using Betel leaf (Piper betle) extracts as reducing, capping, and stabilizing agents. CuO-NPs were characterized using various analytical techniques, including Fourier-transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), highresolution transmission electron microscopy (HRTEM), as well as photoluminescence (PL) measurements. The activity of CuO-NPs was investigated towards Congo red dye degradation, supercapacitor energy storage and antibacterial activity. A maximum of 89% photodegradation of Congo red dye (CR) was obtained. The nanoparticle modified electrode also exhibited a specific capacitance (Csp) of 179 Fg-1. Furthermore, the antibacterial potential of CuO NPs was evaluated against Bacillus subtilis and Pseudomonas aeruginosa, both strains displaying high antibacterial performance.