Typical FESEM images and TEM images of the γ-Mn3O4 spheres with radiated spherulitic nanorods. a: FESEM image at a low magnification, indicating that the γ-Mn3O4 spheres can be fabricated on a large scale. b: FESEM image at a high magnification, revealing the nanorods were fixed on the surfaces of the spheres. c: TEM image of the γ-Mn3O4 radiated spherulitic nanorods. d: The corresponding SAED pattern of the γ-Mn3O4 products.