Hierarchical MOF-808(Zr)/Nb2O5-Bi2S3 nanocomposites on porous polymer scaffold: a dual Z-scheme visible light photocatalyst for the detoxification of carcinogenic and endocrine-disrupting chemicals

In this study, a visible light-responsive ternary heterojunction photocatalyst, MOF-808(Zr)/Nb 2 O 5 -Bi 2 S 3 , is anchored onto a tailor-made translucent porous poly(ethylene glycol dimethacrylate) monolithic scaffold to investigate the simultaneous decontamination of oncogenic hexavalent chromium (Cr(VI)) species and Bisphenol A (BPA), a well-known endocrine disruptor. In MOF-808(Zr)/Nb 2 O 5 -Bi 2 S 3 , MOF-808(Zr) and Nb 2 O 5 contribute to the heterojunction architecture and interfacial charge transfer behavior, while Bi 2 S 3 serves as the visible light harvesting component. The immobilization of MOF-808(Zr)/Nb 2 O 5 -Bi 2 S 3 within the porous polymer monolith (PO-ZNB) establishes a high-efficiency heterogeneous photocatalyst with voluminous adsorption/photoactive sites and interconnected diffusion pathways for the efficient decontamination of pollutants, while also suppressing catalyst aggregation. The structural morphology, surface characteristics, optical, and charge-carrier properties of PO-ZNB are systematically investigated using p-XRD, HR-TEM-SAED, XPS-VB-XPS, FE-SEM-EDX, FT-IR, UV-Vis-DRS, PL, EIS, photocurrent, and BET/BJH analyses. The combined VB-XPS, Mott-Schottky, optical, charge-carrier, and reactive-species analyses support a dual Z-scheme charge-transfer pathway for the PO-ZNB photocatalyst, facilitating ≥ 94.8% Cr(VI) reduction at pH 2.0 and ≥ 96.6% BPA removal at pH 4.0 within 50 min of visible-light irradiation, using 40 mg of the photocatalyst. The photocatalyst maintains its activity across six consecutive cycles, demonstrating excellent reusability, reliability, and structural stability for visible-light-driven decontamination of inorganic/organic pollutants.