A novel method for surface modification of MIL-101 by TiO2 for efficient degradation of dye pollutants

In this study, a TiO₂@CQDs–NH₂@MIL-101(Fe)-NH₂ nanophotocatalyst was synthesized via a surface modification strategy, yielding a highly porous, thermally stable, and low-impurity metal-organic framework. The abundance of amine groups in this structure significantly enhances the synergy between adsorption and photocatalysis. Structural characterization (FT-IR, XRD, DRS, TEM, and TGA) confirmed the nanoscale morphology (16–20 nm) and a narrowed band gap (2.2 eV). The as-prepared photocatalyst efficiently degraded methylene blue (MB) and malachite green (MG) in a neutral aqueous solution under UV irradiation in the presence of H₂O₂, achieving complete degradation within 12 and 15 min, respectively, via a photo-Fenton-like mechanism. Furthermore, the catalyst retained its structural integrity and catalytic activity over multiple consecutive cycles. The combination of rapid UV-driven degradation, mild operational conditions, low catalyst dosage, and environmental compatibility highlights the novelty and practical potential of this nanophotocatalyst for sustainable wastewater treatment. Ultimately, this study significantly advances the design and engineering of next-generation photocatalytic materials by introducing an innovative method to integrate TiO₂@CQDs-NH₂ and MIL-101(Fe)-NH₂ into a monolithic hybrid structure. This synergistic approach combines the semiconductor's inherent photoactive properties with the exceptional charge-shuttling capabilities of amino-functionalized carbon quantum dots and the highly functionalized, cooperative coordination environment of the MOF network, creating a powerful, multifunctional platform for the accelerated remediation of persistent organic pollutants.