100 mg IRMOF-3 powder was dispersed in 10 ml of DMF under ultrasound for 10 min at room temperature. After achieving a homogeneous solution, a Ni(NO3)2•6H2O aqueous solution (10 mg/ml, 50 µL) was gradually added dropwise into the above solution under ultrasound for 5 min at room temperature. Subsequently, the mixed solution was magnetically stirred at room temperature for 3 h. Following the reaction, the powder was collected through centrifugation, washed multiple times with DMF and ethanol, and dried under vacuum at 65 ºC for overnight.