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

Abstract

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 (M_s) (30.25 emu g⁻¹), while the coercivity (H_c) (10.85 Oe) and retentivity (M_r) (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.