2.2.1. Preparation of UiO-66(Zr)-NH2
ZrCl4 (0.5 g) and 2-NH2-BDC (0.536 g) were dissolved in DMF (60 mL), and then, concentrated HCl (percent assay of ~36.0%) (4 mL) was added to the solution. The mixture was sonicated for 20 min to fully dissolve all reagents and was subsequently heated at 80 °C for 24 h in an oven. The UiO-66(Zr)-NH2 powder was collected via centrifugation and was alternately washed with DMF and CHCl3 three times. The obtained nanoparticles were dried at 80 °C for 12 h.