Magnetic Fe3S4/CdS composite: Vis-Fenton reaction to degrade tetracycline hydrochloride

Fenton-like reaction based on Fe 3 S 4 /H 2 O 2 system has been applied in pollutants degradation, but the obvious drawbacks largely hinder its practical uses. Fe 3 S 4 /CdS composites were prepared using a hydrothermal method and tested for photo-Fenton catalytic activity. The degradation activity of the composites was tested using tetracycline hydrochloride (TCH) as an organic pollutant. The study investigated the effects of the mass ratio of Fe 3 S 4 and CdS, catalyst dosage, temperature, pH change, and H 2 O 2 dosage on the degradation of TCH. The study found that the removal rate of TCH by Fe 3 S 4 /CdS was 2.34 and 3.53 times higher than that of pure Fe 3 S 4 and pure CdS, respectively, at 35 °C when the mass ratio of Fe 3 S 4 to CdS was 1:1 and the pH value was 4.2. The Fe 3 S 4 /CdS composites widened the pH range for the Fenton reaction and still showed good degradation of TCH under neutral conditions. The trapping experiments of the active substances revealed that the main active radicals were •O 2 - , while •OH, h + , and e - play a minor role in the degradation of TCH. The catalytic reaction performance was improved by the synergistic effect of CdS and Fe 3 S 4 . Five cycle experiments were conducted on the Fe 3 S 4 /CdS composites, demonstrating their stability and reproducibility.