Mechanism of efficient Fe-MoS₂ synergistic photocatalytic Fenton reaction for tetracycline degradation

To address the environmental residues of tetracycline (TC) antibiotics and the spread of antibiotic resistance genes, as well as to develop efficient synergistic photocatalytic Fenton catalysts, this study synthesized iron-doped molybdenum disulfide (Fe-MoS 2 ) composite catalysts via a hydrothermal method and constructed a synergistic photocatalytic Fenton system for efficient TC degradation. Experimental results showed that the doping of iron significantly optimized the electronic structure of MoS 2 , reducing its bandgap from 1.51 eV to 1.30 eV, thereby broadening its light absorption range. Additionally, Fe Mo dual active sites suppressed charge recombination and improved charge separation efficiency. Under visible light irradiation, Fe-MoS 2 synergistically activated H 2 O 2 , achieving a TC removal rate of 82.3 % within 60 min. Iron doping promoted the heterogeneous Fenton reaction, accelerated the Fe 3+ /Fe 2+ cycling, and facilitated the direct reduction of H 2 O 2 by photogenerated electrons to produce active species ( O 2 − and 1 O 2 ), while the synergistic hole oxidation effectively degraded TC. Fe-MoS 2 exhibited excellent stability in weakly acidic to neutral environments as well as in complex aqueous matrices, along with good recyclability. This study provides new insights for the development of efficient bifunctional catalytic materials and offers significant reference value for the treatment of antibiotic contamination in real wastewater.