Novel Ni/Fe-MIL-53@ZnO nanocomposite for efficient photodegradation of aflatoxins G1 and G2

The photodegradation of aflatoxins G1 and G2 (AFG1 and AFG2) is crucial for mitigating the health risks associated with these potent mycotoxins, as it enhances food safety and protects human health by reducing their persistence and bioavailability in contaminated environments. This study investigates the efficient photodegradation of AFG1 and AFG2 using a novel Bimetallic MIL-53 (Al, Ni)/ZnO nanoparticle composite as a photocatalyst. The catalyst was synthesized in two stages: Chemical synthesis of zinc oxide nanoparticles (ZnO NPs) and hydrothermal synthesis to form the composite. Optimization of a ZnO-based photocatalyst, synthesized by varying proportions of NiCl₂·6H₂O and Al(NO₃)₃·9H₂O, revealed that a 0.547 g:0.864 g ratio maximized photocatalytic degradation of AFG1 and AFG2. Through experimental design, the degradation process was optimized, identifying pH 4.1, 109 mg of photocatalyst, 35 mg L^-1 of AF concentration, and 3 mM of H₂O₂ concentration as optimal conditions. The predicted removal efficiencies for AFG1 and AFG2 were 97.43% and 98.69%, respectively. Kinetic studies utilizing the pseudo-first-order rate equation revealed rate constants of 0.058 ± 0.002 and 0.060 ± 0.003 min^-1 for AFG1 and AFG2, respectively. Additionally, the half-life times for AFG1 and AFG2 photodegradation were found to be 11.95 and 11.55 min, respectively. Catalyst reuse investigations demonstrated that the composite could be reused at least 5 times without significant loss of efficacy. These findings highlight the effectiveness of the Bimetallic MIL-53 (Al, Ni)/ZnO NPs composite as a stable and efficient photocatalyst for the removal of AFG1 and AFG2 under mild conditions, showcasing its potential for practical applications in environmental remediation processes.