Enhanced photodegradation performance and mechanism of MIL-101(Fe)@AgI@TPA/TPB photocatalyst with double Z-scheme heterojunction for oxytetracycline hydrochloride

The residue of oxytetracycline hydrochloride (OTC) has emerged as a significant concern impacting both human health and the ecological environment. Photocatalysis has a good application prospect in the treatment of antibiotic pollution due to its advantages of lost cost, high efficiency and environmental friendliness, and the development of photocatalyst has become crucial for achieving effective photocatalytic degradation. The preparation of Z-scheme heterojunction is regarded as an effective strategy to enhance photocatalytic activity. Herein, double Z-scheme MIL-101(Fe)@AgI@TPA/TPB heterojunction materials were innovatively designed and successfully prepared. MIL-101(Fe)@AgI@TPA/TPB could achieve 95.09 % OTC removal efficiency under visible light irradiation in 70 min. The investigation of photoelectric properties and mechanisms revealed that MIL-101(Fe)@AgI@TPA/TPB had a broader range and enhanced ability for light absorption, along with a narrower band gap. It was determined that ·O 2 - and ·OH were the primary active species involved in the photocatalysis process. The mechanism of double Z-scheme heterojunction capable of facilitating efficient photocatalytic degradation was proposed, and the intermediate products and decomposition pathways of OTC in the photocatalytic degradation process were analyzed. This study provides innovative insights into practical application through the prepared double Z-scheme heterojunction photocatalyst aimed at remediating OTC contamination in water environments.