The Synthesis and Application of the Hollow Mesoporous SiO_2/Dense SiO_2/Fe_3O_4 Composite Particles

摘要

The hollow mesoporous SiO_2/dense SiO_2/Fe_3O_4composite particles with different pore sizes were prepared by a multistep coating technique.TEOS as a silicon source,and P123 were combinated with co-surfactant CTAB as template to coat mesoporous on the dense SiO_2/Fe_3O_4composite particles. The influence of the pore diameter in the composite particle on the laccase immobilization amount in the composite particle and the catalytic efficiency of 2,4-dichlorophenol on hollow composite particles were researched in detail.When the pore diameter of the hollow composite particles was 4.30 nm,the laccase immobilization amount reached the maximum (234 mg/g). The pH was within 3～8 range, and the activity of immobilized laccase was obviously higher than that of free laccase molecule. And the relative activity of immobilized lactase was highest when pH was 4. When the temperature was within 303K ～ 353K,the immobilized laccase had higher relative activity thanfree laccase and the activity of immobilized laccase still remained 28%. The removal rate of 2,4-dichlorophenol of immobilized laccase in the composite particles was about 80%.