MOF-808 nanoparticles were synthesized by microwave irradiation method for different reaction times. As shown in Fig. 1, all the diffraction peaks can be well indexed to crystalline MOF-808, and no diffraction peaks from any other impurities were detected. It demonstrates that we can obtain highly crystalline MOF-808 nanoparticles by this simple, low cost, and environmentally friendly method. In addition, the XRD patterns of the samples obtained in the present work exhibit broad Bragg reflections, suggesting the presence of crystals with small sizes, which was in agreement with the SEM and TEM results. From Fig. 1(f), it could be seen that the peak of the samples B exhibited little intensity change after five cycles, indicating that their microcrystalline form was well remained.