Using a simple solvothermal reaction obtain NH2-MIL-125 (Ti) MOF catalyst referring to our previously reported procedure. 2-aminoterephthalic acid (H2ATA) (2.178 g, 12 mmol) and Ti(OC4H9)4 (1 ml, 3 mmol) were dissolved in 18 ml of N, N-dimethyformamide (DMF) and 2 mL of MeOH to give a brown solution. Then it was transferred into a 50 mL of Teflon-lined autoclave and heated at 150 C for 48 h before it was naturally cooled down to room temperature.