Synthesis, characterisation and photocatalytic activation of zinc nanoparticles via. biogenic methods

Zinc nanoparticles (ZnNPs) were synthesised using a biogenic method from Hypericum calycinum leaves and characterised by UV-Vis spectroscopy, FTIR, TEM, and XRD to assess their optical, structural, and morphological properties. The ZnNPs exhibited absorbance peaks at 274 nm and 370 nm, with an average particle size of 29.066 ± 10.561 nm and a crystalline size of 16 nm. Their photocatalytic efficiency was evaluated by degrading methylene blue (MB) dye under sunlight, achieving 70% degradation in 150 minutes. This study represents the first use of H. calycinum for ZnNP synthesis and demonstrates their potential for photocatalytic dye removal and wastewater treatment applications.