Synthesis of MnFe₂O₄ hollow microspheres via a sacrificial templates approach

Manganese ferrite (MnFe₂O₄) hollow microspheres were synthesized through a sacrificial template approach using manganese carbonate (MnCO₃) microspheres as sacrificial templates. Different from the literatures, the synthesis of MnFe₂O₄ hollow spheres was achieved through a one-pot hydrothermal process without subsequent calcination process. The temperature and reaction time of the hydrothermal process were set to be 180 °C and 8 h. The formation mechanism of the MnFe₂O₄ hollow microspheres was also investigated. Results indicate that the average diameter of the as-synthesized MnFe₂O₄ hollow microspheres is 1.2 μm. The shells of the hollow microspheres are composed of nanoparticles. During hydrothermal process, Mn2⁺ ions diffused outward and resulted in shell materials of MnFe₂O₄, thus MnCO₃ templates were consumed and MnFe₂O₄ hollow microspheres were obtained. (paper)