Z-type composite type II ternary CNFeOS heterojunction composite photocatalyst for enhancing the photocatalytic degradation of tetracycline

In this study, a novel Z-scheme + II-type ternary heterojunction nanocomposite was prepared by one-step solvothermal method using g-C3N4, FeS2 and Fe2O3 as raw materials. The successful preparation of this ternary heterojunction was confirmed by the structural analysis and the surface morphology study. Compared with g-C3N4, the ternary photocatalyst showed excellent photocatalytic performance for the degradation of tetracycline (TC). The enhancement of photocatalytic activity is mainly due to the increase of light absorption capacity, effective separation of carrier in space, and increase of electron transfer channels in this Z-Scheme + II-type composite system. The scavenger test and electron spin resonance spectroscopy show that O2− is the main oxidizing free radical in the photocatalytic system. Based on liquid chromatograph-mass spectrometer, a possible degradation pathway of TC was proposed. This study opens up a new idea for the design and synthesis of efficient Z-Scheme + II-type photocatalysts for environmental purification.