In this study, ZnO nanoparticles were synthesized in an environmentally friendly manner at various pH levels (6, 8, 10, and 12) using fresh betel leaf extract. The effect of pH on optical properties was analyzed using a UV-Vis spectrophotometer. Meanwhile, structural and morphological properties were characterized using X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). FTIR charac…