| In the present work, rare earth doped cobalt ferrite nanoparticles are synthesized by an improved hydrothermal method. The effects of the doping with different rare earth elements or the different doping amounts on the structural and physical properties of cobalt ferrite nanoparticles have been investigated. It can be concluded that the as-synthesized nanoparticles have homogeneous morphology, excellent magnetic properties and high adsorption capacity of Congo red. The main contents are shown as follow:1. CoFe2-xGdxO4 (x=0,0.03,0.05,0.07,0.1) have been synthesized by an improved hydrothermal method. Here, the metal nuclei slurry was gained in a colloid mill mixed with metal cations precursor and reductant sodium borohydride, then the metal nuclei slurry was transferred to autoclaves and reacted under a certain temperature and pressure. XRD、TEM、Raman and VSM are used to characterize the microstructure and magnetic properties. The measurements explored that the obtained samples are pure cubic spinel phase with regular morphology and high saturation magnetization. Meanwhile, the particle size, saturation magnetization and coercivity regularly changed with the increase of the doping amount. Additionally, the doping of Gd3+ ions leads to an obvious enhancement of absorption capability for Congo Red (CR).2. CoFe1.9Re0.1O4 (Re=Pr, Sm, Te, Ho) nanoparticles are synthesized by a modified hydrothermal method. XRD、TEM、FT-IR、EDS and VSM are used to characterize the microstructure and magnetic properties. VU-vis is applied to investigate the absorption capability of cobalt ferrite nanoparticles for Congo Red. Based on the analyses on the absorption kinetics and isotherm model, the absorption kinetics can be described by the pseudo-second-order model, and the isotherm model corresponds to Langmuir isotherm model. This study demonstrates that the addition of rare earth ions can further enhances the adsorption capability of ferrite nanoparticles for dyes and can be regarded as a potential adsorbent. |
PDF Full Text Request