Fe-Driven Specificity and Z-Scheme Catalysis in MOF Nanocomposites for Targeted Discrimination and Degradation of Tetracycline Antibiotics

The integration of detection and degradation capabilities within a single material presents a promising strategy for the management of antibiotic pollutants. Herein, a multifunctional graphitic carbon nitride (g-C3N4)-coupled metal–organic framework (MOF) nanocomposite (denoted as g-C3N4/MIL101) was designed as an all-in-one platform for the sensitive detection and efficient removal of tetracycline antibiotics (TCs). The material architecture combines a Z-scheme heterojunction for enhanced photo-Fenton activity, with Fe3+ sites that serve as specific recognition centers for TCs. This dual design enables the nanocomposite to function as a highly selective colorimetric sensor array, achieving simultaneous discrimination of multiple TCs and non-TC antibiotics. Furthermore, the specific coordination between Fe sites and TCs not only facilitates sensing but also promotes the subsequent degradation by preconcentrating the targets near catalytic centers. Under visible light, the system demonstrates efficient TC degradation with minimized energy and H2O2 input, driven by the enhanced charge separation of the Z-scheme heterojunction and the Fe-mediated Fenton-like process. Theoretical calculations confirm the Fe-node-mediated specific coordination toward TCs, as well as the reduced activation energy for O2 and H2O2 activation of this platform. This work provides a feasible design strategy for multifunctional coordination polymers in advanced environmental applications.