Synthesis of (100) surface oriented MIL-88A-Fe with rod-like structure and its enhanced fenton-like performance for phenol removal

Morphology of MIL-88A-Fe greatly affects their Fenton-like performance. In this work, rod-like, spindle-like and diamond-like MIL-88A-Fe was prepared by changing the ratio of solvents in solvothermal process. Their physicochemical properties are fully investigated by XRD, SEM, TEM, XPS, ESR, and DFT calculation, which confirmed that the exposed (100) ratio of MIL-88A-Fe determined its catalytic performance. The (100) surface of MIL-88A-Fe showed lower energy barrier for H2O2 dissociated into •OH (dissociated energy 0.58 eV), corresponding value is 0.8 eV for (101) surface. The Fenton-like performance has the order of r-MIL-88A (TOF 5.0 h−1) > s-MIL-88A (TOF 3.3 h−1) > d-MIL-88A (TOF 2.5 h−1), when r-MIL-88A used as catalyst, phenol could be removed 100% in 15 min by the help of H2O2 at room conditions, its activity are better than that of reported Fe-based MOFs, such as MIL-88B-Fe, MIL-101-Fe, and MIL-53(Fe) etc. This finding probably provide a Fenton-like catalyst by choosing the suitable crystal phase of Fe-based metal organic framework.