Double Type‐Z Heterojunction UiO‐66/ZIF‐8/AgI for Highly Efficient Photocatalytic Degradation of Tetracycline

ABSTRACT The increasing scarcity of water and energy resources presents substantial challenges to social development. Photocatalytic technology has emerged as a promising solution, capable of degrading water pollutants while utilizing solar energy. However, existing photocatalytic systems encounter limitations, including high costs, low efficiency, potential secondary pollution, and limited stability. In this study, a novel ternary composite photocatalyst, UiO‐66/ZIF‐8/AgI, incorporating a dual Type‐Z heterojunction, was successfully synthesized using solvothermal and precipitation methods. The catalyst was evaluated for its ability to degrade tetracycline (TC) (50 mL, 20 mg/L) under visible light ( λ > 420 nm). When the AgI mass ratio reached 30%, the photocatalytic efficiency peaked at 97.7%, surpassing all other catalysts tested. This remarkable performance is attributed to the high surface area, improved charge carrier separation and transfer efficiency, and extensive visible light absorption range of the catalyst, as confirmed by comprehensive characterization. Superoxide radicals (•O 2 − ) and holes (h + ) were identified as the main active species responsible for degradation through radical trapping experiments and EPR analysis. The optimized 30%‐UZA composite demonstrated excellent TC degradation, introducing a new approach for designing visible light‐driven photocatalysts that are both efficient and stable.