Synthesis of mesoporous Co-spinel ferrite using a hard template and gaseous diffusion

摘要

A new method to synthesize mesoporous Co-spinel ferrites is reported. Co~(2+)Fe~(2+)Fe~(3+)-CO_3~(2-)-Iayered double hydroxides (LDHs) were synthesized by coprecipitation in the presence of porous degreased popped corn and became adsorbed on the pore walls of the popped corn via hydrogen bonding. Mesoporous Co-spinel ferrites with pore sizes ranging from 2.7 nm to 4.2 nm were obtained by calcination of the Co~(2+)Fe~(2+)Fe~(3+)-CO_3~(2-) -LDH/popped corn assembly at 900 °C. Transmission electron microscopy (TEM) images showed that the formation of pores is related to diffusion and egress of CO_2 which was formed during the calcination process. The product is composed of a large number of nanoparticles, and has good soft magnetic properties. This new method is expected to be applicable to the synthesis of other porous materials.