A Simple Synthetic Strategy Toward Recyclable Polyurethane Foam Supported Defective CoFeAl-Layered Double Hydroxides for Antibiotics Photocatalytic Degradation

The recovery of photocatalysts and the photocatalytic efficiency limit the practical application of the photocatalysts. In this work, the photocatalysts loaded on the polyurethane foam (PUF) with defect-rich CoFeAl-LDHs were successfully created and used to photodegrade tetracycline hydrochloride (TC). According to the experimental results, LDH@PUF-20 has a superior visible-light photocatalytic activity for TC (96%) degradation, and its reaction rate constant was 1.6 times greater than that of LDHs. LDH@PUF-20 possessed good recovery and stability during at least three runs, and 80% of TC was degraded after three runs. The introduction of the oxygen vacancies enhances the separation and transfer of the photogenerated carriers through the photoelectrochemical tests. The possible degradation intermediates were determined by LC-MC results, and the pathways for TC degradation was put forward. The superoxide radical was determined as the main active species through the active species capture experiment, and the amount of superoxide radical was also quantified. Finally, a possible photocatalytic mechanism of LDH@PUF-20 for TC degradation under visible light irradiation was proposed.