溶剂热制备纳米Fe_3O_4及其高效Fenton降解4-氯苯酚

Solvothermal Synthesis of Fe_3O_4 Nanoparticles for Efficient Fenton Degradation of 4-Clorophenol

以Fe(NO_3)3·9H_2O为铁源,乙二醇为溶剂和还原剂,采用溶剂热法制备了Fe_3O_4磁性纳米颗粒.利用XRD、FT-IR和TEM对其进行了物相和形貌的表征,以4-氯苯酚(4-CP)为目标污染物,评价了其活化H_2O_2的性能.结果表明:制备的Fe_3O_4纳米颗粒近似呈球形,平均粒径约15 nm,能够有效地活化H_2O_2产生·OH并高效降解4-CP.在25℃,Fe_3O_4用量0.3 g·L^(-1),H_2O_2浓度1.6 mmol·L^(-1),初始pH=5.7时,所建立Fe_3O_4-H_2O_2氧化体系能在15 min内完全降解去除0.4 mmol·L^(-1) 4-CP,较相同条件下超声辅助反相共沉淀法制备的Fe_3O_4效果更好.Fe_3O_4活化H_2O_2降解4-CP的机理主要是因为新的溶剂热法可导致Fe_3O_4磁性纳米颗粒表面的富羟基化和配位作用.

Fe_3O_4 magnetic nanoparticles( MNPs) were prepared through a solvothermal method with Fe( NO3)3·9H_2O as precursor in the presence of ethylene glycol,which acted both as a solvent and reducing agent. The structure and shape of the Fe_3O_4 MNPs were characterized by XRD,FT-IR and TEM. The H_2O_2-activating ability of Fe_3O_4 MNPs was evaluated by using 4-clorophenol( 4-CP) as the target pollutant. The results indicated that the as-prepared spherical Fe_3O_4 MNPs were of diameter of about 15 nm,which showed strong catalytic ability toward the activation of H_2O_2 to produce hydroxyl radicals(·OH),causing efficient degradation of 4-CP. Under the test condition( Fe_3O_40. 3 g·L^(- 1),H_2O_21. 6 mmol·L^(- 1),initial p H 5. 7,25℃),4-CP( 0. 4 mmol·L^(- 1)) can be efficiently degraded within 15 min under the established Fe_3O_4-H_2O_2 oxidation system,reflecting its superior performance than Fe_3O_4 MNPs prepared through ultrasound assisted reverse co-precipitation method. It was speculated that the mechanism of Fe_3O_4 MNPs activated H_2O_2 for 4-CP degradation was attributed to the formation of abundant hydroxyl groups with strong coordination function on the surface of Fe_3O_4 MNPs.