Three-dimensional cobalt microspheres composed of nanosheets assembled via facile hydrothermal method

Abstract We report a template-free approach to prepare three-dimensional cobalt microspheres composed of nanosheets by a facile hydrothermal method. The synthesized 3D cobalt microspheres with diameter of approximately 1–2 µm have a nanosheet of ca . 18 nm. The samples were characterized by X-ray diffraction, SEM, TEM, and VSM techniques. It was found that the initial concentration of Co(NO 3 ) 2 ·4H 2 O and surfactant played an important role in the formation of 3D cobalt microspheres. The Ms value of 3D cobalt microspheres which obtained under the cationic surfactant is about 122.55 emu/g. Due to the specific structure and magnetic properties, these 3D cobalt microspheres are expected to have potential applications as candidates for catalysis, sensor and energy storage.