研究报告
周红艺,胡蝶,曾思思,陈勇.纳米级Fe3O4-Pd/Fe复合材料催化脱氯2,4-D研究[J].环境科学学报,2018,38(2):518-527
纳米级Fe3O4-Pd/Fe复合材料催化脱氯2,4-D研究
- Catalytic dechlorination of 2,4-D in aqueous solution by nanoscale Fe3O4-Pd/Fe composite
- 基金项目：国家自然科学基金（No.20977085）；浙江省自然科学基金（No.Y5100211）
- 作者
- 单位
- 周红艺
- 浙江工业大学环境学院, 杭州 310014
- 胡蝶
- 浙江工业大学环境学院, 杭州 310014
- 曾思思
- 浙江工业大学环境学院, 杭州 310014
- 陈勇
- 浙江工业大学环境学院, 杭州 310014
- 摘要：采用共沉淀法制备纳米级Fe3O4，将其包覆在纳米Pd/Fe颗粒表面制成纳米级Fe3O4-Pd/Fe复合材料，并用于2，4-二氯苯氧乙酸（2，4-D）的催化脱氯.同时，采用透射电镜（TEM）、扫描电镜（SEM）等方法对复合材料的结构进行分析，并考察了初始pH、钯化率、反应温度、纳米Fe3O4投加量等实验参数对nFe3O4-Pd/Fe复合材料催化脱氯2，4-D的影响.结果发现，纳米Fe3O4粒径小于Pd/Fe纳米颗粒，具有一定的磁性，包覆于纳米Pd/Fe表面，提高了纳米材料的稳定性及分散性，并有利于复合材料的回收和循环利用.此外，纳米Fe3O4具有一定的导电性，可作为良好的电子通道为纳米Pd/Fe颗粒传递电子，促进反应的进行，增强2，4-D的去除效果.实验结果表明，较高的钯化率、反应温度、Fe3O4：Fe质量比及中性pH条件均有利于反应的进行.当纳米Fe投加量为1.0 g·L-1，m（Fe3O4）：m（Fe）为1：1，初始pH为7.0，钯化率为0.15%，反应温度为25.0℃时，反应90 min后，40.0 mg·L-1的2，4-D的去除率达到100%，苯氧乙酸（PA）的生成率达99.8%.
- Abstract：In the present study, Fe3O4 nanoparticles were initially prepared and loaded on nano Pd/Fe surface to form nFe3O4-Pd/Fe, and the synthesized composite was used for catalytic dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution. This composites were systematically characterized by using Transmission electron microscope(TEM), Scanning electron microscopy(SEM). Operating parameters including initial pH, palladium loading rate, temperature and dosage of Fe3O4 nanoparticles on 2,4-D reduction were investigated. Results demonstrate that the magnetic Fe3O4 coated on the surface of nanoscale Pd/Fe improved the stability and dispersion capability of nanomaterials. In addition, Fe3O4 served as a good channel for electron transfer from nano Pd/Fe particles and enhanced the removal of 2,4-D. Under the optimized reaction conditions (nFe3O4 1.0 g·L-1, nFe 1.0 g·L-1, T=25.0℃, Pd/Fe=0.15%, n=200 r·min-1, pH=7.0), 40.0 mg·L-1 2,4-D was almost completely converted into phenoxyacetic acid(PA) just in 90 min. The findings from this study suggestes that the dechlorination of 2,4-D by nanoscale Pd/Fe was significantly enhanced with Fe3O4 nanoparticles and can be a promising solution for catalytic dechlorination of 2,4-D.
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