Fabrication of Fe3O4@polydopamine@polyamidoamine core–shell nanocomposites and their application for Cu(II) adsorption

Fe3O4@polydopamine@polyamidoamine (Fe3O4@PDA@PAMAM) core–shell nanocomposites were successfully fabricated through a monodispersed Fe3O4 nanoflower synthesis, PDA modification and PAMAM grafting. The as-prepared single Fe3O4@PDA@PAMAM nanocomposite possesses a high relevant saturation magnetization (Ms) (30.25 emu g−1), while the coercivity (Hc) (10.85 Oe) and retentivity (Mr) (0.9062 emu g−1) were extremely low. The obtained Fe3O4@PDA@PAMAM has an adsorption capacity as high as 97.18 mg g−1 for Cu(II), and the adsorption process is in conformity with pseudo-second-order kinetics and the Langmuir isotherm model. Moreover, the effect of pH and thermodynamics of the adsorption process is also discussed briefly.