Abstract

Nanocomposites based on magnetic Cobalt Ferrite (CoFe2O4) and Cu/Al layered double hydroxide (LDH) particles, and their calcined equivalent CoFe2O4/layered double oxide (LDO) composites, were synthesized, characterized and tested as recoverable adsorbents for Methyl Orange (MO) dye. The nanocomposites presented magnetic behavior that depends on the relative amount of CoFe2O4 with respect to the LDH, allowing their separation under small magnetic fields. Moreover, the presence of CoFe2O4 during the synthesis of LDH largely affected the absorption of MO on both LDH and LDO particles. While pure LDH and LDO showed values of maximum monolayer adsorption capacities (q(e)) of 151 and 807 mg/g, respectively, low amount of CoFe2O4 increased the MO absorption to 262 and 1355 mg/g for LDH and LDO, respectively. High concentrations of CoFe2O4 otherwise decreased the MO adsorption capacity of both layered particles. The higher MO adsorptions in the nanocomposites may be viewed as coming from changes in the layer structure due to the presence of magnetic nanoparticles disrupting the interactions between the platelets. With both their high level of anionic dye adsorption and strong magnetic character, these materials have been posited to form a valuable material for water remediation in the future.