Abstract:

A monolithic macroporous/mesoporous SiO₂ with three-dimensional (3D) continuous pass-through pore structure was prepared by the hard template method. It was the surface functionalized with polydopamine (PDA) by the in situ oxidation polymerization of dopamine in its micro-channels to obtain the macroporous/mesoporous composite PDA/SiO₂. Samples were characterized by SEM，BET，FTIR and TG. PDA/SiO₂ was used to immobilize commercial Novozymes laccase; and the effects of pH，immobilizing time，initial concentration of laccase and temperature on laccase immobilization were investigated. Using azophloxine as a simulated pollutant, the catalytic performance of the immobilized laccase for the degradation of dye was studied. The results showed that the activity of immobilized laccase reached the maximum (348.9U/g) under conditions of initial laccase concentration 80mg/mL，pH of 4.0，immobilizing time of 6h and temperature of 25℃. Up to 99.9% of azophloxine was decolored under azophloxine concentration 10mg/L，pH of 7.0，temperature of 30℃, and degradation time of 8h. The immobilized laccase exhibited good reusability and it can be easily recovered from the reaction system.

Key words: monolithic, macroporous/mesoporous SiO₂, immobilization, laccase, degradation, azophloxine

摘要：

用硬模板法制得具有三维连续贯通孔道结构的整体型大孔/介孔SiO₂，通过多巴胺（DA）在大孔/介孔SiO₂孔道表面的原位氧化聚合，制得聚多巴胺（PDA）功能化修饰的整体型大孔/介孔复合材料（PDA/SiO₂）。应用SEM、BET、FTIR和TG等技术对修饰前后的材料进行表征。以PDA/SiO₂为载体固定诺维信工业级漆酶，系统研究了pH、固定化时间、漆酶初始浓度及温度对漆酶固定化的影响；以偶氮荧光桃红作为模拟污染物，研究了固定化漆酶对染料的催化降解性能。结果显示，在漆酶浓度为80mg/mL、pH为4.0、固定化时间为6h及固定化温度为25℃时，固定化漆酶酶活达到最高（348.9U/g）。在偶氮荧光桃红浓度为10mg/L、pH为7.0、温度为30℃、降解时间为8h时，固定化漆酶对偶氮荧光桃红脱色率 ≥ 99.9%，且固定化漆酶易从反应体系中分离，重复使用性能良好。

关键词: 整体型, 大孔/介孔PDA/SiO₂, 固定化, 漆酶, 降解, 偶氮荧光桃红