فوتوكاتاليست MIL-88 B اصلاح شده با نقاط كوانتومي كربني نيتروژن دار در حذف رنگ متيلن بلو به روش فوتوفنتون

In this study, a composite material consisting of the metal-organic framework MIL-88B(Fe) was synthesized an‎d subsequently functionalized with nitrogen-doped carbon quantum dots (NCQDs). The resulting NCQD@MIL-88B(Fe) composite was characterized using FE-SEM, XRD, FT-IR, BET, an‎d UV-Vis DRS techniques. BET analysis revealed that the incorporation of NCQDs into the MIL-88B(Fe) framework led to a decrease in specific surface area from 120 m²/g to 34.8 m²/g. The synthesized composite was employed as a photocatalyst for the removal of methylene blue dye from aqueous solutions via the photo-Fenton process. Optimal dye removal efficiency was achieved at pH 3. Under these optimized conditions, the composite demonstrated the capability to remove 90.2% of methylene blue (50 ppm) within 120 minutes, with a relative stan‎dard deviation (RSD) of 2.4% an‎d an apparent degradation rate constant (k) of 1.69 × 10⁻² min⁻¹. Total organic carbon (TOC) analysis indicated a 90% mineralization of organic carbon. Adsorption isotherm studies showed that the Freundlich model best described the methylene blue adsorption behavior, with a maximum adsorption capacity of 121.5 mg/g. The results confirm that the synthesized NCQD@MIL-88B(Fe) composite simultaneously functions as both an effective adsorbent an‎d photocatalyst in the photo-Fenton degradation process.

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