Schottky heterojunction-based photocatalysis-in-situ-self-Fenton system: Removal of tetracycline hydrochloride and biotoxicity evaluation of intermediates

Efficiently removing tetracycline hydrochloride (TC) while minimizing the formation of toxic intermediates is a significant challenge. A novel photocatalysis-in-situ-self-Fenton catalyst, RF/EA-Fe@TiC, removed 92 % of TC (20 mg L, 100 mL) under visible light irradiation within 80 min. The results of optical thickness and local volumetric rate of photon absorption demonstrated that RF/EA-Fe@TiC had superior light capture ability than that of RF/EA-Fe. TC significantly inhibited wheat seed germination, seedling growth, and chlorophyll and carotenoid generation, whereas its intermediates had a lesser effect. Additionally, TC damaged the photosystem II (PSII) of wheat seedlings, reducing light response ability and energy capture efficiency, while TC intermediates caused damage similar to deionized water. The rapid TC degradation and low-ecotoxic intermediates stem from the synergistic effects between photogenerated holes and hydroxyl radicals. This study advanced the design of photocatalysis-in-situ-self-Fenton systems for antibiotic degradation and detoxification.