Eco-friendly synthesis of CuO nanoparticles induced by Var. adoensis and its high photocatalytic ability and recyclability

Green synthesis is a viable solution for maintaining industrial ecology and promoting sustainable development. Plant-based product design is a practical way to foresee the global trend in research. In this context, the synthesis of CuO nanoparticles (NPs) using Lippia abyssinica ( Var. adoensis ) leaf extract (CuO-L) and seed extract (CuO-S) is significant. In this study, first, phytochemical screening is performed to detect the reducing and stabilizing agents in the selected plant leaves and seed extracts. Subsequently, CuO NPs are prepared via simple green biosynthesis. The morphology and physicochemical and optical properties of the as-synthesized materials are assessed using X-ray diffraction analysis, scanning-electron microscopy, energy-dispersive X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller analysis, differential reflectance spectroscopy, and photoluminescence measurements. The synthesized NPs are monoclinic with high crystallinity but have different sizes around 10–25 nm and bandgap energies of 1.473 and 1.481 eV for the leaf and seed-induced CuO NPs, respectively. Their photocatalytic activity is tested against that of the most prominent antibiotic, tetracycline. The leaf-induced CuO NPs exhibited relatively high photocatalytic catalytic activity.