Solar Energy-Promoted Bisphenol A Degradation with Immobilized Laccase in an Fe₃O₄-Embedded Metal–Organic Framework

Bisphenol A (BPA) is a well-recognized endocrine-disrupting chemical that poses risks to both human health and the environment. Laccase can effectively biodegrade bisphenol A, but the low environmental temperature (∼25 °C) restricts the biodegradation efficiency. In this study, the enzyme laccase and Fe₃O₄ with solar-thermal conversion capability were coimmobilized into zeolitic imidazolate framework-8 (Lac@ZIF-8-Fe₃O₄) to facilitate efficient biodegradation of bisphenol A under simulated solar irradiation. Compared to free laccase, Lac@ZIF-8-Fe₃O₄ exhibited high activity recovery (115.5%), an ∼39% increased catalytic constant, more effective bisphenol A biodegradation (up to 24-fold) at extensive bisphenol A concentrations (5-100 mg/L), excellent thermal stability (50 °C, 12 h), acid-tolerance (pH 3), and storage ability in 10 days. Simulated solar irradiation (1 kW/m²) increased the temperature of Lac@ZIF-8-Fe₃O₄ solution (10 μg laccase/mL) from 25 to 42.5 °C within 15 min, resulting in 96.4% biodegradation of bisphenol A within 60 min, nearly double the biodegradation efficiency under dark condition (55.9%). Furthermore, Lac@ZIF-8-Fe₃O₄ maintained 99.0% biodegradation efficiency even after 12 recycles of use under simulated solar irradiation (5 mg/L bisphenol A, 80 min/cycle). This work has thus offered efficient biocatalysis for integrating solar-energy promotion and enzymatic catalysis in treating environmental BPA pollutants. Further, the experimental findings benefited from the development of more sustainable and high-performance immobilized enzyme preparations for pollutant treatment via solar-thermal promotions.