利用金属还原菌Shewanella oneidensis MR-1在Fe₃O₄微球上原位负载钯纳米颗粒，成功合成了Pd/Fe₃O₄磁性复合材料并对其进行表征分析。Pd/Fe₃O₄磁性纳米复合材料能催化硼氢化钠还原对硝基苯酚等硝基芳香化合物，反应30 min后，对硝基苯酚（4-NP）的去除率可达98%。Pd/Fe₃O₄磁性复合材料在室温下具有超顺磁性，在外加磁场条件下即可快速从反应液中分离出来和重复利用，且重复利用10次后4-NP去除率依然超过86%，具有良好的稳定性。该生物合成方法不需要有害的试剂，而且解决了生物钯的回收和重复利用问题，为贵金属纳米复合材料的发展开辟了一条新的、环境友好的途径。

Recyclable precious metal nano-catalysts have broad application prospects in green chemistry.Pd/Fe₃O₄ magnetic composites are successfully synthesized through loading palladium nanoparticles in-situ on Fe₃O₄ microspheres by means of metal-reducing bacteria Shewanella oneidensis MR-1,and then characterized by different technical measures.Pd/Fe₃O₄ magnetic composites can catalyze the reduction of nitroaromatic compounds such as p-nitrophenol by sodium borohydride.After 30 minutes of reaction,the removal rate of p-nitrophenol can reach 98%.Pd/Fe₃O₄ magnetic composites exhibit super paramagnetism at room temperature,can be quickly separated from the reaction solution under external magnetic field conditions and reused in the next cycle reaction.After the composites have been reused for 10 times,the removal rate over them still exceeds 86%,showing a good stability.This bio-synthesis method does not require harmful reagents and solves the problem of bio-palladium recycling,which opens up a new environmental friendly way for the development of precious metal nanocomposites.

谢韦(1996-),女,硕士研究生,研究方向为环境微生物,1148201467@qq.com