An Efficient Fe ₃ O ₄ /BiOI _1/3 Cl _2/3 Heterostructure Catalyst for the Tetracycline Degradation Under Visible Light

Abstract A novel heterostructure photocatalyst composed of Fe 3 O 4 /BiOI 1/3 Cl 2/3 microspheres was fabricated via a facile coprecipitation method and comprehensively characterized by XRD, SEM, XPS, BET, DRS and zeta potential analysis. The photocatalytic performance of the Fe 3 O 4 /BiOI 1/3 Cl 2/3 heterostructure for the tetracycline (TC) degradation with visible light irradiation (λ > 420 nm) was evaluated, achieving a degradation efficiency of 91.3% after 60 mins. This performance was significantly better than Fe 3 O 4 /BiOCl reference. Moreover, Fe 3 O 4 /BiOI 1/3 Cl 2/3 showed the best activity under neutral conditions (pH = 7). The exceptional photocatalytic efficiency of Fe 3 O 4 /BiOI 1/3 Cl 2/3 might be attributed to its significant absorption in the visible spectrum, coupled with a reduced rate of recombination of electron‐hole pairs. Furthermore, two main reactive oxidation species were identified, from which h + and O 2 •− contributed to approximately 85.3% and 14.0%, respectively, to the TC degradation. The degradation byproducts were examined using liquid chromatography‐mass spectrometry, and potential degradation pathways for TC were suggested. Toxicities of these products were also evaluated.