The intrinsic peroxidase-like activity of magnetite (Fe3O4) has to be improved to activate H2O2 under mild conditions for practical applications. Herein fluorinated Fe3O4 microspheres (F-Fe3O4-r, r: 0.1-3), where r indicates the F/Fe molar ratio in the reaction mixture, were prepared by glycothermal synthesis and characterized by various complementary techniques. Fluoride ions were enriched on the surface of F-Fe3O4-1, and may substitute lattice oxygen or ion-exchange with surface hydroxyl groups. Kinetic study showed that the apparent activation energy for catalytic decomposition of H2O2 over F-Fe3O4-1 was significantly lower than those over unmodified Fe3O4 or other heterogeneous peroxidase-like catalysts (20.3 vs. 32.8-142 kJ mol(-1)), which improved the low-temperature activity of the former (decomposition rate of H2O2 at 25 degrees C: 0.0150 h(-1)). Potential applications of F-Fe3O4-1 in wastewater treatment were demonstrated by catalytic degradation of orange G with H2O2 at pH 6.8 and 25 degrees C. (C) 2019 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.