A hierarchically porous MgFe2O4/γ-Fe2O3 magnetic microspheres for efficient removals of dye and pharmaceutical from water

Hierarchically porous MgFe2O4/γ-Fe2O3 magnetic microspheres were reported as novel efficient adsorbent for the removals of dye and pharmaceutical from water. The spontaneous formation and organization of nanoparticles of MgFe2O4 on γ-Fe2O3 matrix was based on a cheap, nontoxic and facile technique involving using pine pollen as template. The as-prepared pollen-morphic MgFe2O4/γ-Fe2O3 exhibited hierarchically porous structure composed of nanocrystallites with grain sizes of 8 nm. The adsorption kinetics equilibrium and thermodynamics of congo red (CR) and minocycline (MC) onto MgFe2O4/γ-Fe2O3 and γ-Fe2O3 were investigated. The as-synthesized magnetic microspheres exhibited excellent adsorption performances. Maximum adsorption capacities of 259.1 mg/g and 200.8 mg/g were obtained for congo red and minocycline, respectively. The adsorption kinetics and isotherm of congo red and minocycline onto the as-synthesized samples followed the pseudo-second-order and Langmuir monolayer model, respectively, and the adsorption processes were spontaneous and endothermic in nature. The adsorbed samples could be regenerated by methanol or NaOH solution, and easily magnetically separated from aqueous solution. The synthesized materials might act as excellent adsorbents for environmental processes.