Hybrid solvothermal/sonochemical-mediated synthesis of ZnO NPs generative of OH radicals: Photoluminescent approach to evaluate OH scavenging activity of Egyptian and Yemeni Punica granatum arils extract

•Solvothermal/sonochemical route was employed to prepare ZnO NPs.•These ZnO NPs is highly generative of hydroxyl radicals upon Solar-irradiation.•The OH were trapped and probed via selective/sensitive fluorimetric monitoring.•This suits a novel/precise avenue to evaluate OH scavenging activity of Punica granatum arils.•Results sensitively account for superior efficacy of natural antioxidant over synthetic one.