Copper Oxide Nanoparticles: Characterization, Photocatalysis, and Biomedical Applications

Abstract Current synthesis methods for copper oxide nanoparticles (CuO NPs) use toxic chemicals, limiting their environmental and biomedical use. We used green synthesis with potato starch as a reducing and stabilizing agent, hypothesizing it would yield CuO NPs with enhanced photocatalytic and antimicrobial properties due to unique structures. X‐ray diffraction (XRD) confirmed a 13.92 nm crystallite size, scanning electron microscopy (SEM) showed flake‐like aggregates, and ultraviolet (UV)–Vis revealed a 2.95 eV bandgap, indicating strong optical properties. CuO NPs achieved 99.2 % degradation of Evans Blue dye in 140 min and full atrazine degradation in 160 min, showing excellent photocatalysis. Antimicrobial assays gave inhibition zones up to 26 mm for bacteria and 14 mm for fungi at 20 mg mL −1 . These results show potato starch–synthesized CuO NPs’ potential for environmental remediation and antimicrobial applications, offering a sustainable option for nanomaterial synthesis.