抄録
MIL-101 (Fe) (MIL = Matériaux de l'Institut Lavoisier) was used to fabricate MIL-101 (Fe)-NH2 by replacing the 1,4-benzenedicarboxylate (BDC) ligand with 2-aminoterephthalate (BDC-NH2), wherein substituent NH2 was introduced into the crystal structure. Powder X-ray diffraction and Fe K-edge X-ray absorption fine structure (XAFS) studies revealed that MIL-101 (Fe) had a crystal structure different from that of MIL-101 (Fe)-NH2, and the local structure around the Fe ion in their bulk did not change. However, Fe L-edge XAFS studies revealed that the Fe ions on the surface of MIL-101 (Fe) were reduced, indicating that the change in electronic structures on the surface could affect the electrochemical properties of MIL-101 (Fe). Charge–discharge measurements of lithium-ion batteries, with either MIL-101 (Fe) or MIL-101 (Fe)-NH2 as the positive electrode active material, showed that batteries with MIL-101 (Fe)-NH2 electrodes had a higher capacity and initial potential than those with MIL-101 (Fe) electrodes. These results suggest that the chemical structure on the surface of MIL-101 (Fe) affected its capacity and initial potential.
