Hierarchical nanoplatform for integrated detection and degradation of chloramphenicol:surface enrichment, confined enhancement and phosphate complexation.

The development of bifunctional platform capable of integrated recognition and elimination of trace contaminant residues remains a key challenge for water environmental monitoring. This work, the zirconium-based metal-organic frameworks (Zr-MOFs) featuring a dual-functional interfacial layered architecture was rationally designed and constructed, enabling both the sensitive detection and efficient degradation of chloramphenicol (CAP). Leveraging the surface enrichment and confined enhancement, both the detection and degradation performance of the hierarchical nanoplatform have been significantly boosted. The photoelectrochemical (PEC) sensing unit exhibited a good linear response to CAP in the range of 0.01 pg mL-1 to 100 ng mL-1 with a detection limit as low as 1.51 fg mL-1, while the oxidative degradation unit could eliminate more than 80% of the CAP within 10 min and 95% within 60 min. Experimental characterizations demonstrate that the confined catalysis generated PO43- can significantly enhance the PEC detection and oxidative degradation performance of Zr-MOFs through surface enrichment, confined enhancement and surface phosphate complexation. Theoretical calculations indicate the electron distribution of the lowest unoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) was disrupted after PO43- complexation, which promotes the activation of molecular oxygen and enhances the degradation efficiency of CAP. Finally, the potential degradation pathways of CAP were systematically investigated, and the associated biological toxicity was comprehensively evaluated. It is expected that this study will provide valuable insights into the coupling of sensitive monitoring and efficient treatment for water pollutants.