Metronidazole photocatalytic degradation by zinc oxide …
The watermelon rinds extract was prepared by mixing dried watermelon rind powder (10 g) with distilled water (50 mL). The mixture was boiled for 20 min at 85 °C. The extract was then filtered using Whatman® cellulose filter paper. ZnO NPs were synthesized by mixing 50 mL of zinc acetate solution (0.25 M) with 10 mL of watermelon extract.