Herein, the MgO nanorods were successfully synthesized via a facile, novel and solvent-free thermal
decomposition route at low temperature using Mg–MOF as a new starting reagent for the first time. The
Mg–MOF was prepared via fast microwave-based method using 2,6-pyridinedicarboxylic acid ammonium and Mg(NO3)2 2H2O. Furthermore, the efficiency of MgO nanostructures as a photocatalyst for
decolorization of methylene blue (MB) under visible light irradiation has been evaluated. The synthesized MgO nanostructures exhibited appreciable photocatalytic activity and in presence of MgO, 90%
degradation of MB was obtained after 180 min.