Synthesis and magnetic properties of crystalline mesoporous CoFe2O4 with large specific surface area

Based on the nanocasting strategy, highly crystalline mesoporous CoFe2O4 were synthesized for the first time through the pyrolysis of hybrid metal nitrates within the pores of two kinds of mesoporous silica, SBA-15 and KIT-6, respectively. The Brunauer-Emmet-Teller (BET) surface areas of the samples could be as high as 155.7 m(2) g(-1) (templated by SBA-15) and 129.4 m(2) g(-1) (templated by KIT-6). Characterization results revealed that the mesoporous structures of the templates can be negatively replicated by the crystals of CoFe2O4 and the probable phase formation mechanism was also proposed initially. Magnetic test showed that both samples had rather low coercivity (106.5 and 212.1 Oe, respectively) due to the presence of a prominent proportion of superparamagnetic particles. It has also been found that the impregnation steps had a great influence on the stucture and properties of the products.