Mn doped Fe-gallate acid MOFs loaded on the surface of biomass cotton fibers: Fenton-like degradation of tetracycline.

In this study, the novel composite material was synthesized by loading Mn-doped Fe-based gallic acid metal-organic frameworks (MOFs) onto biomass cotton fibers (Mn/Fe-GA-MOFs@CF). Mn doping improved the catalytic efficiency of Fenton-like reactions. Moreover, the MOFs loading onto cotton fibers enhanced the recoverability and practical usability. The Mn/Fe-GA-MOFs@CF + HO system achieved a 90.30 % removal efficiency for tetracycline (TC) within 50 min. In addition, the reaction system exhibited a broad pH tolerance (2-9), relatively good resistance to interference from common anions and cations, and good reusability. Free radical quenching experiments and electron paramagnetic resonance (EPR) analysis confirmed that hydroxyl radical (•OH) was the primary active species in the degradation reaction, and the Mn doping accelerated the generation of free radicals. Meanwhile, the environmental friendliness of Mn/Fe-GA-MOFs@CF was enhanced by using gallic acid replaced typical organic ligand. Additionally, seed germination tests indicated that the TC-degraded solution was significantly less toxic while also promoting mung bean root growth. In conclusion, this study provides a sustainable strategy for green catalysts and offers theoretical and technical insights into the application of Fenton-like processes for organic wastewater treatment.