Fe3O4 magnetic nanocomposites combined with graphene oxide (GO) and carbon nanotubes (CNTs) are synthesized by a hydrothermal method, followed by synthesis of GO/CNT–Fe3O4 supported Pd nanoparticles using a gas–liquid interfacial plasma (GLIP) method with Pd(OAc)2 as a precursor, and the Pd nanoparticles show a uniform particle size distribution. The catalysts exhibit remarkable catalytic activity during the hydrogenation of nitroarenes under H2 atmosphere at 60 °C in water using a small amount of catalyst, and the catalyst can be magnetically separated from the reaction mixture. The addition of the Fe3O4 component to the GO/CNTs can be used to effectively prevent aggregation and restacking of GO and the CNTs, and the GO/CNT composite can adjust the hydrophilic–hydrophobic property of the catalysts. Furthermore, the Pd catalyst can be readily recovered and reused several times without a significant decrease in activity. It is worth mentioning that the Pd-3 catalysts show remarkable activity during C–H functionalization.
