The photocatalytic degradation of acetaminophen (ACT) in the Ag/ZnO@NiFe₂O₄/PMS/UVA system was investigated through comprehensive mechanistic analysis. Scavenger experiments using oxalate (OX), p-benzoquinone (BQ), tert-butyl alcohol (TBA), and ethanol (EtOH) revealed that hydroxyl radicals (HO•), sulfate radicals (SO₄•⁻), photogenerated holes (h⁺), and superoxide radicals (O₂•⁻) all contributed to ACT degradation. The significant inhibition observed with TBA and EtOH indicated that HO• and SO₄•⁻ were dominant species, with TBA reacting approximately 1000 times faster with HO• than with SO₄•⁻. The calculated rate constant for the reaction between TBA and HO• (3.6–7.6 × 10⁸ M⁻¹ s⁻¹) was substantially higher than that between TBA and SO₄•⁻ (4.441798-33-0 custom synthesis 0–9.1 × 10⁵ M⁻¹ s⁻¹), confirming the primary role of HO•. Similarly, EtOH showed a strong quenching effect, supporting the involvement of both radical types. Based on band edge potential calculations, the conduction band (CB) of ZnO (-0.12 eV) is more negative than that of NiFe₂O₄ (-0.79 eV), enabling electron transfer from ZnO to NiFe₂O₄. Photogenerated electrons in the CB of ZnO are efficiently captured by Ag NPs due to their high Fermi level, suppressing electron-hole recombination and enhancing O₂ reduction to form O₂•⁻. Meanwhile, photogenerated holes in the valence band (VB) of ZnO (+3.0 eV) can directly oxidize ACT or react with H₂O/OH⁻ to produce HO•. The presence of PMS further amplifies radical generation: it acts as an electron acceptor, forming SO₄•⁻ and HO• via redox cycling of Fe³⁺/Fe²⁺ and Ni²⁺/Ni³⁺. Additionally, surface-bound O₂•⁻ can decompose PMS and water molecules to yield SO₄•⁻ and HO•, respectively. These synergistic pathways collectively enhance the oxidative capacity of the system. LC-MS analysis identified eleven transformation products, including hydroxylated intermediates (e.g., TP1, TP4), benzoquinones (TP8), carboxylic acids (TP5, TP10), and nitrate (TP7), indicating sequential hydroxylation, ring opening, deamination, and mineralization.ERCC1 Antibody Protocol The formation of nitrate suggests effective oxidation of nitrogen-containing bonds in ACT.PMID:35223815 A detailed degradation pathway was proposed, illustrating how radical attack initiates aromatic ring hydroxylation, followed by cleavage of C–N and C–C bonds, ultimately leading to complete mineralization into CO₂ and H₂O. This study provides a clear mechanistic framework for the radical-based degradation of organic pollutants in MOF-derived photocatalytic systems activated by PMS under UVA light.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com