Photocatalytic\nDegradation of Antiviral Drugs Chloroquine\nPhosphate and Lamivudine by Bi<sub>2</sub>O<sub>3</sub>–TiO<sub>2</sub>/PAC under a Xe Lamp: Insights into Reactive Oxygen Species’\nAction and Toxicity R

Recently, owing to the prevalence of epidemic and pandemic\nviral\ndiseases, the widespread use of antiviral drugs (ATVs) such as chloroquine\nphosphate (CQ) and lamivudine (3TC) has raised environmental concerns\nregarding their presence in wastewater. In this study, we explore\nour previously developed Bi<sub>2</sub>O<sub>3</sub>-doped TiO<sub>2</sub> composites supported by powdered activated carbon (Bi<sub>2</sub>O<sub>3</sub>–TiO<sub>2</sub>/PAC; BT/C) catalysts\nfor degrading CQ and 3TC as a green and efficient approach. Under\nsuitable conditions (C<sub>0</sub>[ATV] = 10 mg/L, pH = 7, and catalyst\ndose = 250 mg/L), the degradation rates of CQ and 3TC reached 95.1%\nand 57.1% after radiation for 30 and 120 min, respectively. <i>In situ</i> irradiation X-ray photoelectron spectroscopy results\nand density functional theory simulations confirmed that BT/C enhanced\ninterfacial electron transfer from TiO<sub>2</sub> to Bi<sub>2</sub>O<sub>3</sub> and suppressed carrier recombination. Quenching experiments\nand electron paramagnetic resonance results confirmed ·O<sub>2</sub><sup>–</sup> generation, leading to subsequent ·OH\nand <sup>1</sup>O<sub>2</sub> production. In addition, degradation\npathways for CQ and 3TC were proposed. Toxicity assessments indicated\nreduced overall toxicity during photocatalysis. BT/C catalysts proved\neffective across diverse water qualities and maintained stable performance\nthrough repeated use. This study offers new insights into photocatalytic\nATV-removal mechanisms and opens avenues for innovative hybrid treatment\ntechnologies.