Effect of bee-pollen extract on the green synthesis of CuO nanoparticles

The environmentally friendly synthesis of cupric oxide nanoparticles using biological approaches has shown great promise as an alternative to expensive and user-unfriendly conventional methods. In this study, bee pollen extract was used for the first time as a simple and economical method for the biosynthesis of CuO nanoparticles at room temperature without the adding of harmful chemical solvents. The effect of the amount of BP on the structural, optical, and morphological properties of CuO nanoparticles was examined using different analytical methods. According to the XRD results, CuO nanoparticles prepared with the lowest amount of BP exhibited the smallest average size (19.57 nm), maximum dislocation and micro strain density, and a high degree of crystallinity. FTIR results confirmed that the Cu–O bond was formed by the possible functional groups of the biomolecules present in the bee pollen extract. UV and visible emission peaks were observed in the PL spectra, demonstrating the good optical properties of the BP products. It was found that the optical energy band gap decreased from 1.485 eV to 1.408 eV as the amount of BP increased. Moreover, the amount of BP significantly influenced the morphological properties of the CuO nanoparticles. At low amounts, spherical and pseudo-spherical shapes of CuO nanoparticles were observed, while at higher amounts, strong aggregation/agglomeration of these nanoparticles was observed. The purity of the as-synthesized CuO nanoparticles was assessed by EDX characterization. Graphical abstract