Study on the Structure of Fe/BiOCl0.1I0.9 Composite Photocatalyst and Its Degradation Performance for TC‐HCl

Abstract The overuse of antibiotics has emerged as a significant threat to water security, necessitating the development of advanced photocatalysts with efficient charge carrier separation. In this study, a porous microsphere‐structured Fe/BiOCl 0.1 I 0.9 photocatalyst was successfully synthesized via a one‐step solvothermal method. Comprehensive characterizations, including XRD, SEM, XPS, UV–vis DRS, photocurrent (PC) response, and electrochemical impedance spectroscopy (EIS), were conducted to elucidate its structural and optical properties. The photocatalyst exhibited outstanding degradation performance against tetracycline hydrochloride (TC‐HCl), achieving a 93% removal rate within 60 min under visible light. The degradation followed pseudo‐first‐order kinetics, with a rate constant 2.2 times that of pristine BiOCl. The Fe 3 ⁺ doping and solid solution strategy synergistically regulated the band structure, enlarged the surface area, and promoted charge separation, thereby enhancing both light absorption and photocatalytic activity. The material demonstrated stable performance across a wide pH range (3–9) and in the presence of coexisting anions such as Cl⁻ and NO₃⁻. Radical trapping experiments identified superoxide radicals (•O 2 ⁻) and holes (h⁺) as the primary active species. These findings offer a promising approach to designing dual‐modified BiOX‐based photocatalysts for effective removal of antibiotic pollutants in water treatment.