Oriented anchoring of NCQD on citric acid defective cluster of NH2-MIL-88B(Fe) for the efficient removal of tetracycline via photo-Fenton catalysis

Surface modification and material composition are promising strategies for metal organic framework (MOF) to achieve excellent organic pollutant degradation performance. However, forming functional units inside MOF catalyst exactly at their active sites to improve charge dynamics remains challenges. Herein, oriented anchoring strategy was proposed to anchor nitrogen-doped carbon quantum dots (NCQDs) with defective cluster of NH2-MIL-88B(Fe) (NM8B) for highly efficient catalytic degradation tetracycline (TC) via synergistic photo-Fenton catalysis. The unique pyramidal charge transmission region connected by C-N-C=O significantly promoted the charge kinetics from NCQDs to citric acid anchored NM8B, constructed Lewis acidic sites and strong ligand vacancies in CG-QDs@C20-NM8B. The combination promoted the separation of photo-generated electron-hole pairs, redox capability of Fe (II)/Fe (III) in MOF and enhanced the self-corrosion resistant stability. As a consequence, 93 % TC was oxidized (200 mg/L) in 30 min, showing ultra-fast degradation capacity of 527 mol center dot min(-1)center dot g(-1), that rise 3-84 times higher than the reported renowned catalysts. In addition, the CG-QDs@C20-NM8B catalyst exhibited almost identical catalytic performance after 20 times reuse, exhibiting outstanding recycling performance than many reported MOFs. These intriguing merits rank CG-QDs@C20-NM8B as an efficient and promising choice for the degradation of TC from wastewater.