Visible light photocatalytic activity of a FeCo metal-organic framework for degradation of acetaminophen and 2,4-dichlorophenoxyacetic acid and a nematode-based ecological assessment

The present work reports the solvothermal synthesis of a bimetallic (FeCo) metal-organic framework (MOF) for the sunlight-driven photocatalytic degradation of acetaminophen (AAP) and 2,4-dichlorophenoxyacetic acid (2,4-D). The FeCo-MOF was confirmed by various analytical techniques. The as-prepared FeCo-MOF displayed improved light absorbance in the visible region and a bandgap energy of 1.73 eV. Photoluminescence spectra showed that the FeCo-MOF exhibited a lower charge carrier recombination rate than bare Fe- or Co-MOFs. The FeCo-MOF achieved a maximum AAP conversion rate (rate constant 0.031/min) of 97.4% in 180 min than bare Fe-MOF (66%) or Co-MOF (73%). A scavenger study showed that the superoxide anion radicals were responsible for the degradations of AAP and 2,4-D. The catalyst proved stable after five recycles with no change in AAP degradation efficiency. On the other hand, under the same conditions, the FeCo-MOF photodegraded 2,4-D by 79.8%. A kinetic study showed that the degradations of AAP and 2,4-D exhibited pseudo-first-order kinetics. In addition, the ecotoxicity results showed that degraded 2,4-D altered the survival, development, reproduction, intracellular redox status, and expression pattern of stress-responsive genes in the Caenorhabditis elegans model.