<i>Polyalthia longifolia</i>-mediated green synthesis of zinc oxide nanoparticles: characterization, photocatalytic and antifungal activities

Abstract

The biological synthesis of zinc oxide nanoparticles (ZnO NPs) from plant extracts has emerged as a novel method for producing NPs with great scalability and biocompatibility. The present study is focused on bio-fabricated zinc oxide nanomaterial characterization and investigation of its photocatalytic and antifungal activities. ZnO NPs were biosynthesized using the leaf extract of <i>Polyalthia longifolia</i> without using harmful reducing or capping chemicals, which demonstrated fungicidal activity against <i>Fusarium oxysporum</i> f. sp. <i>ciceris</i>. The results showed that the inhibition of the radial growth of <i>F</i>. <i>oxysporum</i> f. sp. <i>ciceris</i> was enhanced as the concentration increased from 100 ppm to 300 ppm. The effectiveness of the photocatalytic activity of biosynthesized ZnO NPs was analyzed using MB dye degradation in aqueous medium under ultraviolet (UV) radiation and natural sunlight. After four consecutive cycles, the photocatalytic degradation of MB was stable and was 84%, 83%, 83%, and 83%, respectively, during natural sunlight exposure. Under the UV sources, degradation reached 92%, 89%, 88%, and 87%, respectively, in 90 minutes. This study suggests that the ZnO NPs obtained from plant extract have outstanding photocatalytic and antifungal activities against <i>F. oxysporum</i> f. sp. <i>ciceris</i> and have the potential for application as a natural pest control agent to reduce pathogenesis.