Phytochemical-assisted synthesis of Zn/TiO₂ for continuous-flow photocatalytic degradation of endocrine-disrupting cmpounds

The contamination of aquatic environments by endocrine-disrupting compounds (EDCs), including bisphenol derivatives, poses a growing challenge to water quality and the sustainability of aquaculture systems. In this study, Zn/TiO₂ photocatalysts were synthesized via a green route using maple leaf extract, which acts as a natural source of polyphenols to mediate metal ion coordination and regulate crystal growth during material formation. Structural and optical characterizations confirmed the successful formation of Zn/TiO₂ with uniform elemental distribution of Zn within the TiO₂ matrix. Photocatalytic experiments showed that Zn/TiO₂ exhibited significantly improved degradation of bisphenol A (BPA) as a representative model EDC compared to pristine TiO₂, with the reaction kinetics following a pseudo-first-order model under flow conditions with a rate constant (k) of 0.0215 min⁻¹ . The degradation is controlled by hydroxyl radicals (•OH) as the dominant reactive species, achieving up to 98% degradation efficiency within 180 min. Importantly, the photocatalyst maintained high performance in real water matrices, where concurrent decreases in BPA concentration, UV₂₅₄ absorbance, and TOC, together with minimal pH variation, confirmed effective degradation and partial mineralization without substantial alteration of water chemistry. These findings demonstrate that green-synthesized Zn/TiO₂ is a robust and sustainable photocatalyst for the removal of endocrine-disrupting compounds, offering strong potential for practical application in aquaculture and broader environmental water treatment systems.