Effective Degradation of Tetracycline by Sr‐Doped Bi ₂₄ O ₃₁ Cl ₁₀ ‐Based Photocatalyst: Synthesis, Kinetics, and Mechanism

Abstract Bi 24 O 31 Cl 10 is a representative non‐stoichiometric bismuth‐based photocatalyst. However, it still faces critical challenges in practical applications. These include rapid recombination of photogenerated carriers, limited pollutant degradation universality, and insufficient structural stability. In this study, Sr‐doped Bi 24 O 31 Cl 10 photocatalysts are successfully synthesized via a hydrothermal method. Characterization results demonstrate that Sr doping significantly enhances the separation and migration efficiency of photogenerated electron–hole pairs. The photocatalytic activity is evaluated by degrading 100 mL of 20 mg L −1 tetracycline hydrochloride (TC‐HCl) under simulated sunlight irradiation. After 120 min, the optimized Sr‐Bi 24 O 31 Cl 10 sample achieves a degradation efficiency of 83.9%, with a reaction rate constant (0.0176 min −1 ) 2.1 times higher than that of pristine Bi 24 O 31 Cl 10 . Radical trapping experiments confirm that O 2 − · and h + are the dominant active species. Furthermore, Sr incorporation markedly improves the cycling stability of Bi 24 O 31 Cl 10 . This work presents an effective doping strategy for developing efficient and stable bismuth‐based photocatalysts.