Synthesis of Uniformly Covered Fe-MOF@COF Heterostructures for Boosting Photo-Fenton Catalysis.

Fe-based MOFs (Fe-MOFs) are excellent photocatalysts and have synergy well with Fenton reagents relative to other MOFs. In this work, a series of uniformly covered NH2-Fe-MIL-88B@TpPa-1-COF composites were synthesized using an in-situ anchoring growth strategy, which used F127 as functional molecule to decorate NH2-Fe-MIL-88B nanoparticles to eliminate their surface electrostatic repulsion with Tp molecules during the subsequent coating procedure. Meanwhile, the -NH2 groups in the skeleton of NH2-Fe-MIL-88B could also be used as anchors to covalently connect TpPa-1-COF shell and migration channels for effective charge transfer. This uniformly covered core–shell structure would endow these composites with much more contact area and imine bond linkage between the Fe-MOFs core and COFs shell. Compared with the random packing structure, the uniformly covered Fe-MOF@COF-3 composite possessed a higher proportion of Fe2+ to Fe3+. As a result, the optimized Fe-MOF@COF-3 catalyst could achieve the highest photo-Fenton degradation efficiency of 93.9% for tetracycline hydrochloride (TC⋅HCl), which was much higher than 54.8% of pure NH2-Fe-MIL-88B. In addition, the uniform TpPa-1-COF shell could further effectively enhance the stability of NH2-Fe-MIL-88B by protecting Fe ions from leaching, and the toxicity of the water samples treated with our photo-Fenton degradation process declined obviously. All these merits will endow Fe-MOF@COF-3 photo-Fenton catalyst great potential application value as in the field of environmental governance. [ABSTRACT FROM AUTHOR]