Synthesis of Monodispersed Nanospheres of Mn₃O₄ and Its Adsorption Behavior for Alizarin Red

Abstract

Monodispersed nanospheres of Mn₃O₄ with an average diameter of 5–20 nm have been prepared by a simple reactions between MnSO₄, NH₃·H₂O, and H₂O₂ in the presence of methyl cellulose at 60°C. Methyl cellulose played a decisive role as an inhibitor of the direct attack of H₂O₂ to Mn(OH)₂ surfaces and coagulation of the growing Mn₃O₄ in producing the monodispersed nanospheres. The product was characterized by x-ray powder diffraction and transmission electron microscopy. The adsorption performance of monodispersed nanospheres of Mn₃O₄ for alizarin red was investigated. The nano-adsorbent showed high efficiency for the removal of alizarin red. The equilibrium of adsorption was achieved within 5 minutes. The isotherm adsorption data obeyed the Langmuir model, with a maximum adsorption capacity of 28.72 mg g⁻¹.

Keywords:

• Adsorption
• alizarin red
• Mn₃O₄
• monodispersed nanospheres

Acknowledgments

This work was supported by the Nature Science Foundation of Hubei Province (2004ABA095) and the National Nature Science Foundation of China (Nos. 60171004).