Optimizing CuO nanoparticle synthesis via walnut green husk extract utilizing response surface methodology

•The production of phyto-synthesized CuO NPs was optimized using CCD-RSM.•A statistically significant and adequate linear model described the process.•The optimized NPs were monodisperse with a mean hydrodynamic diameter of 82.61 nm. Fabrication of CuO nanoparticles (NPs), popular nanostructures, through green synthesis using plant extracts, offers distinct advantages, fostering their broad application. In this study, CuO NPs were synthesized utilizing walnut green husk aqueous extract, and their production was optimized by investigating the impact of three factors: extract volume, copper acetate concentration, and reaction time, employing response surface methodology (RSM) with a face-centered central composite design (CCD). A statistically significant and adequate linear model (p-value