Sustainable preparation of Ag-ZnO nanocomposites using Persea americana peel extract for superior antibacterial, antioxidant, and photocatalytic efficacy

Zinc oxide nanoparticles (ZnO NPs) are valued for their stability, low toxicity, and biocompatibility, but their use is limited by fast electron-hole recombination and poor visible light absorption. To address this, silver doping has been explored, with plant extracts offering a green synthesis route. In this study, ZnO NPs and silver-doped ZnO nanocomposites (Ag–ZnO NCs) were synthesized using Persea americana (avocado) peel extract via co-precipitation. The extract acted as both a reducing and stabilizing agent. Characterization (XRD, FT-IR, UV–Vis, SEM) confirmed crystalline structures with average sizes of 14.70 nm (ZnO NPs) and 21.38 nm (Ag–ZnO NCs), and band gap reductions to 3.20 eV and 2.85 eV. Ag–ZnO NCs showed strong antibacterial activity, with inhibition zones of 20 ± 1.2 mm (Bacillus cereus), 19 ± 0.2 mm (Salmonella typhi), and 18 ± 0.5 mm (Staphylococcus aureus). They also exhibited 82.01 % DPPH radical scavenging and 95.9 % methylene blue dye degradation. These results highlight the eco-friendly Ag–ZnO NCs as promising candidates for antibacterial, antioxidant, and environmental applications.