Sunlight‐Driven Photocatalytic Degradation of Brilliant Green Dye by ZnO Nanoparticles: Comparison of ZnO Synthesized With Use of Juniperus Chinensis to Commercial ZnO

Green, plant‐extract‐mediated synthesis routes provide an effective and facile approach to producing nano‐photocatalysts with tunable physical and chemical properties. In the current study, we synthesized biogenic zinc oxide nanoparticles (M‐1 ZnO NPs) using Juniperus chinensis ( J. chinensis ) leaf extract and compared their native properties and sunlight‐assisted photocatalytic activity with those of commercial ZnO nanoparticles (M‐2 ZnO NPs). Flower‐like morphologies of ZnO nanoparticles were obtained from SEM images. The mean crystallite sizes were determined to be 29 nm and 32.02 nm using the Scherrer method, and the band gap was calculated to be 3.19 and 3.20 eV for M‐1 and M‐2, respectively. The use of J. chinensis leaves extract in ZnO NPs synthesis resulted in a smaller particle size, the presence of biomolecules on the surface, and better monodispersity than commercial ZnO. Furthermore, the M‐1 ZnO NPs exhibited higher efficiency in sunlight‐assisted photocatalytic degradation of the brilliant green (BG) dye than M‐2 ZnO NPs. Under sunlight exposure at a catalyst dose of 20 mg M‐1 ZnO, 98.89% photodegradation was achieved in a 50 ppm BG dye solution within just 90 min, with a rate constant of 0.034 min −1 , which was 16.21% higher than that of M‐2 ZnO NPs.