In the present study, a green one-pot low-temperature method is adopted for the synthesis of a novel magnetic graphene nanocomposite catalyst. Graphene preparation is performed without employing any oxidizing agents or corrosive chemicals, under mild sonication in isopropyl alcohol - water mixture. Monolayered nanoplatelets of graphene are obtained in the green solvent mixture and the composite material is found to be ferromagnetic in nature, obvious from the vibrating sample magnetometric measurements. Fe in the nanocomposite exists in two different forms i.e., α-Fe₂O₃ and α-FeOOH, as evident from the material characterization results. The graphene nanocomposite is found to be highly efficient in the selective reduction of nitrobenzene to aniline under solvent free reaction conditions and magnetic separation of this fine nanomaterial from the reaction mixture is successfully carried out. The catalyst is efficiently reusable till five repeated cycles.

本研究采用绿色的一锅法低温合成新型磁性石墨烯纳米复合催化剂。在异丙醇-水混合物中进行温和超声处理时，无需使用任何氧化剂或腐蚀性化学物质即可进行石墨烯制备。在绿色溶剂混合物中获得了石墨烯的单层纳米片，并且发现该复合材料本质上是铁磁性的，这从振动样品的磁力测量中可以明显看出。铁在纳米复合材料中存在的两种不同形式，即，的α-Fe ₂ ö ₃从材料表征结果可以明显看出，α-FeO​​OH和α-FeO​​OH。发现石墨烯纳米复合材料在无溶剂反应条件下能高效地将硝基苯选择性还原为苯胺，并且已成功地从反应混合物中进行了这种精细纳米材料的磁分离。该催化剂可有效地重复使用至五个重复循环。